diff --git a/HISTORY.asc b/HISTORY.asc
index 7e6369e..31138df 100644
--- a/HISTORY.asc
+++ b/HISTORY.asc
@@ -6,6 +6,27 @@ extension_drop depends on cat_tools, which already requires PostgreSQL
 too (a cat_tools function it calls needs PG11+ internally) -- this
 just makes the declared floor honest.
 
+== Run drop commands when `DROP SCHEMA ... CASCADE` or `DROP OWNED BY` drops an extension
+The event trigger now fires for `DROP SCHEMA` and `DROP OWNED` as well as
+`DROP EXTENSION`, and returns immediately unless an extension is among the
+dropped objects, so other drops are unaffected. Previously the other two
+commands skipped the registered SQL and left a stale registration that made
+every later `DROP EXTENSION` fail with `XD001`; remove any existing stale
+registration with `extension_drop__repair()`.
+
+Dropping an unregistered extension (by any of the three commands) needs only
+USAGE on the extension's schema, to resolve the new `SECURITY DEFINER`
+function `extension_drop__registered()` (executable by `PUBLIC`), which the
+trigger asks which of the dropped extensions are registered; it needs no
+privileges on `extension_drop__commands`. Dropping a registered extension
+additionally needs SELECT and DELETE on that table. A role without the access
+gets an `insufficient_privilege` error that names the table, its owner and
+the extensions being dropped, with the underlying error as DETAIL and a HINT
+giving the grants that fix it, instead of `permission denied for table
+extension_drop__commands` or `type "extension_drop__commands" does not
+exist`. The registered SQL runs as the caller and may need further
+privileges.
+
 == Remove redundant client_min_messages handling from install script
 `CREATE EXTENSION` already raises `client_min_messages` to `WARNING` for
 the install script (only-raising, so a stricter caller is respected) and
diff --git a/README.md b/README.md
index 13aecec..5106949 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,13 @@ arbitrary SQL to run later. Grant them to specific roles as needed.
   Look up the row (`extension_name`, `sql`) registered for `extension_name`.
   Granted to `PUBLIC` by default.
 
+- `extension_drop__registered(extension_names name[]) RETURNS name[]`
+  Returns those of `extension_names` that have registered drop commands, and
+  asserts the table is sane when there are none. `SECURITY DEFINER` (with
+  `search_path` pinned to the extension's schema, then `pg_temp`); used by
+  the event trigger so dropping an unregistered extension needs no table
+  access. Granted to `PUBLIC` by default.
+
 - `extension_drop__sanity_check(ignore name DEFAULT NULL) RETURNS name[]`
   Returns the names of extensions that have registered drop commands but no
   longer exist. Should always return an empty array; pass an extension name
@@ -42,6 +49,19 @@ arbitrary SQL to run later. Grant them to specific roles as needed.
 ## How it works
 
 An event trigger (`extension_drop`, on `sql_drop`) fires whenever an
-extension is dropped, runs any SQL registered for it via
-`extension_drop__add`/`extension_drop__update`, and removes the registration
-afterward.
+extension is dropped -- by `DROP EXTENSION`, `DROP SCHEMA ... CASCADE` or
+`DROP OWNED BY` -- removes its registration from `extension_drop__commands`
+and runs the SQL registered for it via
+`extension_drop__add`/`extension_drop__update`. Those commands fire the
+trigger for every drop, but it returns immediately unless an extension is
+among the dropped objects.
+
+Dropping an unregistered extension needs only USAGE on the extension's
+schema (to resolve `extension_drop__registered()`, a `SECURITY DEFINER`
+function executable by `PUBLIC`, which the trigger asks which of the dropped
+extensions are registered); it needs no privileges on `extension_drop__commands`.
+Dropping a registered extension additionally needs SELECT and DELETE on that
+table. A role without the access gets an `insufficient_privilege` error that
+names the table, its owner and the extensions being dropped, with the
+underlying error as DETAIL and a HINT giving the grants that fix it. The
+registered SQL runs as the caller and may need further privileges.
diff --git a/sql/extension_drop--0.1.1--stable.sql b/sql/extension_drop--0.1.1--stable.sql
index b011c62..bd552f0 100644
--- a/sql/extension_drop--0.1.1--stable.sql
+++ b/sql/extension_drop--0.1.1--stable.sql
@@ -1,20 +1,117 @@
+/*
+ * The install script's create_function doesn't exist here, so build the helper directly; see
+ * extension_drop.sql for why it is SECURITY DEFINER with pg_temp last on its search_path.
+ */
+DO $do$
+DECLARE
+  sp text;
+BEGIN
+  SELECT pg_catalog.format('%I', n.nspname) INTO sp
+    FROM pg_catalog.pg_extension e JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace
+    WHERE e.extname = 'extension_drop';
+  EXECUTE pg_catalog.format($f$
+CREATE OR REPLACE FUNCTION extension_drop__registered(
+  extension_names name[]
+) RETURNS name[] LANGUAGE plpgsql STABLE SECURITY DEFINER SET search_path = %s, pg_temp AS
+$body$
+DECLARE
+  ret name[] := array(
+    SELECT extension_name FROM extension_drop__commands WHERE extension_name = ANY(extension_names) ORDER BY 1
+  );
+BEGIN
+  -- With nothing registered the trigger returns without its own assert, so any stray row is a stale one.
+  IF ret = '{}'::name[] THEN
+    PERFORM extension_drop__sanity_assert();
+  END IF;
+  RETURN ret;
+END
+$body$
+$f$, sp);
+END
+$do$;
+REVOKE ALL ON FUNCTION extension_drop__registered(name[]) FROM public;
+GRANT EXECUTE ON FUNCTION extension_drop__registered(name[]) TO public;
+COMMENT ON FUNCTION extension_drop__registered(name[]) IS
+  $$Returns the given extensions that have drop commands, after asserting the table is sane if there are none.$$;
+
 CREATE OR REPLACE FUNCTION extension_drop__event_trigger(
 ) RETURNS event_trigger LANGUAGE plpgsql SET search_path FROM CURRENT AS
 $body$
 DECLARE
-  r extension_drop__commands;
+  t record;
+  dropping text;
+  dropped name[];
+  registered name[];
+  names text[];
+  cmds text[];
+  i int;
+  msg text;
 BEGIN
   RAISE DEBUG 'extension_drop event trigger entry: tg_event %, tg_tag %', tg_event, tg_tag;
-  FOR r IN
-    SELECT c.*
-      FROM extension_drop__commands c
-        JOIN pg_event_trigger_dropped_objects() d
-          ON c.extension_name = d.object_name
-            AND d.object_type = 'extension'
-  LOOP
-    RAISE DEBUG E'extension "%" is being dropped; executing SQL:\n%', r.extension_name, r.sql;
-    EXECUTE r.sql;
-    DELETE FROM extension_drop__commands WHERE extension_name = r.extension_name;
+
+  -- Most drops involve no extension; don't touch our table (or assert) for them.
+  SELECT pg_catalog.string_agg(pg_catalog.quote_ident(object_name), ', ' ORDER BY object_name)
+      , pg_catalog.array_agg(object_name::name ORDER BY object_name)
+    INTO dropping, dropped
+    FROM pg_catalog.pg_event_trigger_dropped_objects()
+    WHERE object_type = 'extension';
+  IF dropping IS NULL THEN
+    RETURN;
+  END IF;
+
+  /*
+   * Callers without table access can still drop unregistered extensions. Without USAGE on our schema the
+   * helper isn't found; fall through to the DELETE below for its clearer error.
+   */
+  BEGIN
+    registered := extension_drop__registered(dropped);
+  EXCEPTION WHEN undefined_function OR insufficient_privilege THEN
+    registered := NULL;
+  END;
+  IF registered = '{}'::name[] THEN
+    RETURN;
+  END IF;
+
+  /*
+   * One statement touches the table, so a privilege error here is ours; registered SQL runs after the
+   * handler so its own errors pass through untouched.
+   */
+  BEGIN
+    WITH del AS (
+      DELETE FROM extension_drop__commands c
+        USING pg_catalog.pg_event_trigger_dropped_objects() d
+        WHERE c.extension_name = d.object_name AND d.object_type = 'extension'
+        RETURNING c.extension_name, c.sql
+    )
+    SELECT pg_catalog.array_agg(extension_name), pg_catalog.array_agg(sql) INTO names, cmds FROM del;
+  EXCEPTION WHEN insufficient_privilege OR undefined_table THEN
+    -- undefined_table: name lookup skips a schema the caller lacks USAGE on, so the table "doesn't exist".
+    GET STACKED DIAGNOSTICS msg = MESSAGE_TEXT;
+
+    -- Look up the table by OID path, not by name, for the same reason.
+    SELECT n.nspname, c.relname, pg_catalog.format('%I.%I', n.nspname, c.relname) AS qname, pg_catalog.pg_get_userbyid(c.relowner) AS owner
+      INTO t
+      FROM pg_catalog.pg_extension e
+        JOIN pg_catalog.pg_class c
+          ON c.relnamespace = e.extnamespace AND c.relname = 'extension_drop__commands'
+        JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
+      WHERE e.extname = 'extension_drop';
+    IF NOT FOUND THEN
+      RAISE;
+    END IF;
+
+    RAISE EXCEPTION 'permission denied for table "%"."%" (owned by role "%"), which extension_drop needs to drop extension(s) %'
+        , t.nspname, t.relname, t.owner, dropping
+      USING ERRCODE = 'insufficient_privilege'
+        , DETAIL = msg
+        , HINT = pg_catalog.format(
+            'Run the drop as role %s or a superuser, or grant USAGE on schema %s and SELECT, DELETE on %s to the current role.'
+            , pg_catalog.quote_ident(t.owner), pg_catalog.quote_ident(t.nspname), t.qname);
+  END;
+
+  FOR i IN 1 .. COALESCE(pg_catalog.array_length(cmds, 1), 0) LOOP
+    RAISE DEBUG E'extension "%" is being dropped; executing SQL:\n%', names[i], cmds[i];
+    EXECUTE cmds[i];
   END LOOP;
 
   /*
@@ -25,4 +122,12 @@ BEGIN
 END
 $body$;
 
+-- ALTER EVENT TRIGGER can't change WHEN
+DROP EVENT TRIGGER extension_drop;
+CREATE EVENT TRIGGER extension_drop
+  ON sql_drop
+  WHEN tag IN( 'DROP EXTENSION', 'DROP SCHEMA', 'DROP OWNED' ) -- NOTE! This MUST be IN
+  EXECUTE PROCEDURE extension_drop__event_trigger()
+;
+
 -- vim: sw=2 ts=2 expandtab
diff --git a/sql/extension_drop.sql b/sql/extension_drop.sql
index 75319be..5987f05 100644
--- a/sql/extension_drop.sql
+++ b/sql/extension_drop.sql
@@ -37,10 +37,24 @@ CREATE FUNCTION __extension_drop.create_function(
 DECLARE
   c_clean_args text := cat_tools.routine__parse_arg_types_text(args);
 
+  -- A definer function must not search pg_temp ahead of its own schema, so pin the path explicitly.
+  search_path_clause text := CASE
+    WHEN options ~* 'security\s+definer' THEN COALESCE(
+      (
+        SELECT pg_catalog.format('= %I, pg_temp', n.nspname)
+          FROM pg_catalog.pg_extension e JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace
+          WHERE e.extname = 'extension_drop'
+      )
+      -- Not running as an extension script (e.g. the build smoke test)
+      , pg_catalog.format('= %I, pg_temp', pg_catalog.current_schema())
+    )
+    ELSE 'FROM CURRENT'
+  END;
+
   create_template CONSTANT text := $template$
 CREATE OR REPLACE FUNCTION %s(
 %s
-) RETURNS %s SET search_path FROM CURRENT AS
+) RETURNS %s SET search_path %s AS
 %L
 $template$
   ;
@@ -71,7 +85,8 @@ BEGIN
       create_template
       , function_name
       , args
-      , options -- TODO: Force search_path if options ~* 'definer'
+      , options
+      , search_path_clause
       , body
     ) )
   ;
@@ -255,6 +270,37 @@ $body$
   , '' -- Just revoke all access
 );
 
+/*
+ * REGISTERED
+ */
+/*
+ * SECURITY DEFINER so the trigger can tell whether a dropped extension is registered without the caller
+ * needing table access; reads only, never runs registered SQL. The path is pinned with pg_temp last
+ * (see create_function) so a caller's temp table can't shadow ours.
+ */
+SELECT __extension_drop.create_function(
+  'extension_drop__registered'
+  , $$
+  extension_names name[]
+$$
+  , 'name[] LANGUAGE plpgsql STABLE SECURITY DEFINER'
+  , $body$
+DECLARE
+  ret name[] := array(
+    SELECT extension_name FROM extension_drop__commands WHERE extension_name = ANY(extension_names) ORDER BY 1
+  );
+BEGIN
+  -- With nothing registered the trigger returns without its own assert, so any stray row is a stale one.
+  IF ret = '{}'::name[] THEN
+    PERFORM extension_drop__sanity_assert();
+  END IF;
+  RETURN ret;
+END
+$body$
+  , $$Returns the given extensions that have drop commands, after asserting the table is sane if there are none.$$
+  , 'public'
+);
+
 /*
  * TRIGGER FUNCTION
  */
@@ -264,19 +310,80 @@ SELECT __extension_drop.create_function(
   , 'event_trigger LANGUAGE plpgsql'
   , $body$
 DECLARE
-  r extension_drop__commands;
+  t record;
+  dropping text;
+  dropped name[];
+  registered name[];
+  names text[];
+  cmds text[];
+  i int;
+  msg text;
 BEGIN
   RAISE DEBUG 'extension_drop event trigger entry: tg_event %, tg_tag %', tg_event, tg_tag;
-  FOR r IN
-    SELECT c.*
-      FROM extension_drop__commands c
-        JOIN pg_event_trigger_dropped_objects() d
-          ON c.extension_name = d.object_name
-            AND d.object_type = 'extension'
-  LOOP
-    RAISE DEBUG E'extension "%" is being dropped; executing SQL:\n%', r.extension_name, r.sql;
-    EXECUTE r.sql;
-    DELETE FROM extension_drop__commands WHERE extension_name = r.extension_name;
+
+  -- Most drops involve no extension; don't touch our table (or assert) for them.
+  SELECT pg_catalog.string_agg(pg_catalog.quote_ident(object_name), ', ' ORDER BY object_name)
+      , pg_catalog.array_agg(object_name::name ORDER BY object_name)
+    INTO dropping, dropped
+    FROM pg_catalog.pg_event_trigger_dropped_objects()
+    WHERE object_type = 'extension';
+  IF dropping IS NULL THEN
+    RETURN;
+  END IF;
+
+  /*
+   * Callers without table access can still drop unregistered extensions. Without USAGE on our schema the
+   * helper isn't found; fall through to the DELETE below for its clearer error.
+   */
+  BEGIN
+    registered := extension_drop__registered(dropped);
+  EXCEPTION WHEN undefined_function OR insufficient_privilege THEN
+    registered := NULL;
+  END;
+  IF registered = '{}'::name[] THEN
+    RETURN;
+  END IF;
+
+  /*
+   * One statement touches the table, so a privilege error here is ours; registered SQL runs after the
+   * handler so its own errors pass through untouched.
+   */
+  BEGIN
+    WITH del AS (
+      DELETE FROM extension_drop__commands c
+        USING pg_catalog.pg_event_trigger_dropped_objects() d
+        WHERE c.extension_name = d.object_name AND d.object_type = 'extension'
+        RETURNING c.extension_name, c.sql
+    )
+    SELECT pg_catalog.array_agg(extension_name), pg_catalog.array_agg(sql) INTO names, cmds FROM del;
+  EXCEPTION WHEN insufficient_privilege OR undefined_table THEN
+    -- undefined_table: name lookup skips a schema the caller lacks USAGE on, so the table "doesn't exist".
+    GET STACKED DIAGNOSTICS msg = MESSAGE_TEXT;
+
+    -- Look up the table by OID path, not by name, for the same reason.
+    SELECT n.nspname, c.relname, pg_catalog.format('%I.%I', n.nspname, c.relname) AS qname, pg_catalog.pg_get_userbyid(c.relowner) AS owner
+      INTO t
+      FROM pg_catalog.pg_extension e
+        JOIN pg_catalog.pg_class c
+          ON c.relnamespace = e.extnamespace AND c.relname = 'extension_drop__commands'
+        JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
+      WHERE e.extname = 'extension_drop';
+    IF NOT FOUND THEN
+      RAISE;
+    END IF;
+
+    RAISE EXCEPTION 'permission denied for table "%"."%" (owned by role "%"), which extension_drop needs to drop extension(s) %'
+        , t.nspname, t.relname, t.owner, dropping
+      USING ERRCODE = 'insufficient_privilege'
+        , DETAIL = msg
+        , HINT = pg_catalog.format(
+            'Run the drop as role %s or a superuser, or grant USAGE on schema %s and SELECT, DELETE on %s to the current role.'
+            , pg_catalog.quote_ident(t.owner), pg_catalog.quote_ident(t.nspname), t.qname);
+  END;
+
+  FOR i IN 1 .. COALESCE(pg_catalog.array_length(cmds, 1), 0) LOOP
+    RAISE DEBUG E'extension "%" is being dropped; executing SQL:\n%', names[i], cmds[i];
+    EXECUTE cmds[i];
   END LOOP;
 
   /*
@@ -291,7 +398,8 @@ $body$
 
 CREATE EVENT TRIGGER extension_drop
   ON sql_drop
-  WHEN tag IN( 'DROP EXTENSION' ) -- NOTE! This MUST be IN
+  -- DROP SCHEMA CASCADE and DROP OWNED BY also drop extensions.
+  WHEN tag IN( 'DROP EXTENSION', 'DROP SCHEMA', 'DROP OWNED' ) -- NOTE! This MUST be IN
   EXECUTE PROCEDURE extension_drop__event_trigger()
 ;
 
diff --git a/test/build/expected/build.out b/test/build/expected/build.out
index 44215eb..c66ee3c 100644
--- a/test/build/expected/build.out
+++ b/test/build/expected/build.out
@@ -19,4 +19,6 @@ INSTALL
 
  
 
+ 
+
 # TRANSACTION INTENTIONALLY LEFT OPEN
diff --git a/test/expected/drop_denied.out b/test/expected/drop_denied.out
new file mode 100644
index 0000000..25f61f4
--- /dev/null
+++ b/test/expected/drop_denied.out
@@ -0,0 +1,63 @@
+\set ECHO none
+1..60
+ok 1 - Create non-superuser role
+ok 2 - Create schema owned by role containing a registered extension
+ok 3 - Registered: DROP SCHEMA CASCADE without USAGE on extension_drop's schema
+ok 4 - Capture DETAIL and HINT
+ok 5 - DETAIL
+ok 6 - HINT
+ok 7 - Grant USAGE on extension_drop's schema
+ok 8 - Registered: DROP SCHEMA CASCADE with USAGE but no table privileges
+ok 9 - Capture DETAIL
+ok 10 - DETAIL is the original error
+ok 11 - Grant SELECT
+ok 12 - Registered: DROP SCHEMA CASCADE with SELECT but not DELETE
+ok 13 - Grant DELETE, register SQL that needs CREATEROLE
+ok 14 - Registered SQL's own privilege error surfaces unchanged
+ok 15 - Register harmless SQL
+ok 16 - Registered: DROP SCHEMA CASCADE with the privileges the HINT names
+ok 17 - No stale registration
+ok 18 - Registration removed
+ok 19 - Recreate the registered extension
+ok 20 - Move the grants from the role to a group it belongs to
+ok 21 - Registered: DROP SCHEMA CASCADE with the privileges held through a group role
+ok 22 - Remove all of the role's access
+ok 23 - Recreate the extension
+ok 24 - Unregister the extension
+ok 25 - Unregistered: DROP SCHEMA CASCADE without USAGE on extension_drop's schema
+ok 26 - Grant USAGE on extension_drop's schema
+ok 27 - Unregistered: DROP SCHEMA CASCADE with USAGE but no table privileges
+ok 28 - Recreate the extension
+ok 29 - Unregister the extension
+ok 30 - Unregistered: DROP OWNED BY with USAGE but no table privileges
+ok 31 - Recreate the extension
+ok 32 - Unregister the extension
+ok 33 - Grant SELECT
+ok 34 - Unregistered: DROP SCHEMA CASCADE with SELECT but not DELETE
+ok 35 - Revoke SELECT
+ok 36 - Recreate the extension
+ok 37 - Unregister the extension
+ok 38 - Revoke EXECUTE on the helper
+ok 39 - Unregistered: DROP SCHEMA CASCADE without EXECUTE on the helper or table privileges
+ok 40 - Restore EXECUTE on the helper
+ok 41 - Superuser drop schema
+ok 42 - Recreate the registered extension
+ok 43 - Registered extension is still found when the caller has a temp table of the same name
+ok 44 - Unregister the extension
+ok 45 - Superuser drop schema
+ok 46 - Recreate the extension
+ok 47 - Unregister the extension
+ok 48 - Insert a stale registration
+ok 49 - Unregistered: DROP SCHEMA CASCADE with a stale registration present
+ok 50 - Repair
+ok 51 - Superuser drop schema
+ok 52 - Create role
+ok 53 - Create test extension as role
+ok 54 - Demote role
+ok 55 - DROP EXTENSION by the extension's non-superuser owner
+ok 56 - Unregister the extension
+ok 57 - Grant USAGE on extension_drop's schema
+ok 58 - Unregistered: DROP EXTENSION by the extension's non-superuser owner with USAGE but no table privileges
+ok 59 - No stale registration
+ok 60 - extension_drop's schema should not be reachable via search_path
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/expected/drop_denied_1.out b/test/expected/drop_denied_1.out
new file mode 100644
index 0000000..741f476
--- /dev/null
+++ b/test/expected/drop_denied_1.out
@@ -0,0 +1,63 @@
+\set ECHO none
+1..60
+ok 1 - Create non-superuser role
+ok 2 - Create schema owned by role containing a registered extension
+ok 3 - Registered: DROP SCHEMA CASCADE without USAGE on extension_drop's schema
+ok 4 - Capture DETAIL and HINT
+ok 5 - DETAIL
+ok 6 - HINT
+ok 7 - Grant USAGE on extension_drop's schema
+ok 8 - Registered: DROP SCHEMA CASCADE with USAGE but no table privileges
+ok 9 - Capture DETAIL
+ok 10 - DETAIL is the original error
+ok 11 - Grant SELECT
+ok 12 - Registered: DROP SCHEMA CASCADE with SELECT but not DELETE
+ok 13 - Grant DELETE, register SQL that needs CREATEROLE
+ok 14 - Registered SQL's own privilege error surfaces unchanged
+ok 15 - Register harmless SQL
+ok 16 - Registered: DROP SCHEMA CASCADE with the privileges the HINT names
+ok 17 - No stale registration
+ok 18 - Registration removed
+ok 19 - Recreate the registered extension
+ok 20 - Move the grants from the role to a group it belongs to
+ok 21 - Registered: DROP SCHEMA CASCADE with the privileges held through a group role
+ok 22 - Remove all of the role's access
+ok 23 - Recreate the extension
+ok 24 - Unregister the extension
+ok 25 # SKIP existing mode: the role can use extension_drop's schema
+ok 26 - Grant USAGE on extension_drop's schema
+ok 27 - Unregistered: DROP SCHEMA CASCADE with USAGE but no table privileges
+ok 28 - Recreate the extension
+ok 29 - Unregister the extension
+ok 30 - Unregistered: DROP OWNED BY with USAGE but no table privileges
+ok 31 - Recreate the extension
+ok 32 - Unregister the extension
+ok 33 - Grant SELECT
+ok 34 - Unregistered: DROP SCHEMA CASCADE with SELECT but not DELETE
+ok 35 - Revoke SELECT
+ok 36 - Recreate the extension
+ok 37 - Unregister the extension
+ok 38 - Revoke EXECUTE on the helper
+ok 39 - Unregistered: DROP SCHEMA CASCADE without EXECUTE on the helper or table privileges
+ok 40 - Restore EXECUTE on the helper
+ok 41 - Superuser drop schema
+ok 42 - Recreate the registered extension
+ok 43 - Registered extension is still found when the caller has a temp table of the same name
+ok 44 - Unregister the extension
+ok 45 - Superuser drop schema
+ok 46 - Recreate the extension
+ok 47 - Unregister the extension
+ok 48 - Insert a stale registration
+ok 49 - Unregistered: DROP SCHEMA CASCADE with a stale registration present
+ok 50 - Repair
+ok 51 - Superuser drop schema
+ok 52 - Create role
+ok 53 - Create test extension as role
+ok 54 - Demote role
+ok 55 - DROP EXTENSION by the extension's non-superuser owner
+ok 56 - Unregister the extension
+ok 57 - Grant USAGE on extension_drop's schema
+ok 58 - Unregistered: DROP EXTENSION by the extension's non-superuser owner with USAGE but no table privileges
+ok 59 - No stale registration
+ok 60 # SKIP existing mode: extension_drop's placement is outside this suite's control
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/expected/drop_owned.out b/test/expected/drop_owned.out
new file mode 100644
index 0000000..36d377c
--- /dev/null
+++ b/test/expected/drop_owned.out
@@ -0,0 +1,16 @@
+\set ECHO none
+1..13
+ok 1 - Insert into extension_drop_test_table
+ok 2 - Create role
+ok 3 - Create test extension as role
+ok 4 - Verify extension_drop__get()
+ok 5 - Drop owned
+ok 6 - Test extension does not exist
+ok 7 - extension_drop_test_table is empty
+ok 8 - No stale registration
+ok 9 - Create test extension
+ok 10 - Test extension exists
+ok 11 - Drop test extension
+ok 12 - Test extension does not exist
+ok 13 - extension_drop's schema should not be reachable via search_path
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/expected/drop_owned_1.out b/test/expected/drop_owned_1.out
new file mode 100644
index 0000000..3801831
--- /dev/null
+++ b/test/expected/drop_owned_1.out
@@ -0,0 +1,16 @@
+\set ECHO none
+1..13
+ok 1 - Insert into extension_drop_test_table
+ok 2 - Create role
+ok 3 - Create test extension as role
+ok 4 - Verify extension_drop__get()
+ok 5 - Drop owned
+ok 6 - Test extension does not exist
+ok 7 - extension_drop_test_table is empty
+ok 8 - No stale registration
+ok 9 - Create test extension
+ok 10 - Test extension exists
+ok 11 - Drop test extension
+ok 12 - Test extension does not exist
+ok 13 # SKIP existing mode: extension_drop's placement is outside this suite's control
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/expected/drop_schema_cascade.out b/test/expected/drop_schema_cascade.out
new file mode 100644
index 0000000..e280978
--- /dev/null
+++ b/test/expected/drop_schema_cascade.out
@@ -0,0 +1,16 @@
+\set ECHO none
+1..13
+ok 1 - Insert into extension_drop_test_table
+ok 2 - Create schema
+ok 3 - Create test extension in schema
+ok 4 - Verify extension_drop__get()
+ok 5 - Drop schema cascade
+ok 6 - Test extension does not exist
+ok 7 - extension_drop_test_table is empty
+ok 8 - No stale registration
+ok 9 - Create test extension
+ok 10 - Test extension exists
+ok 11 - Drop test extension
+ok 12 - Test extension does not exist
+ok 13 - extension_drop's schema should not be reachable via search_path
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/expected/drop_schema_cascade_1.out b/test/expected/drop_schema_cascade_1.out
new file mode 100644
index 0000000..a634d57
--- /dev/null
+++ b/test/expected/drop_schema_cascade_1.out
@@ -0,0 +1,16 @@
+\set ECHO none
+1..13
+ok 1 - Insert into extension_drop_test_table
+ok 2 - Create schema
+ok 3 - Create test extension in schema
+ok 4 - Verify extension_drop__get()
+ok 5 - Drop schema cascade
+ok 6 - Test extension does not exist
+ok 7 - extension_drop_test_table is empty
+ok 8 - No stale registration
+ok 9 - Create test extension
+ok 10 - Test extension exists
+ok 11 - Drop test extension
+ok 12 - Test extension does not exist
+ok 13 # SKIP existing mode: extension_drop's placement is outside this suite's control
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/expected/unrelated_drops.out b/test/expected/unrelated_drops.out
new file mode 100644
index 0000000..fdf0059
--- /dev/null
+++ b/test/expected/unrelated_drops.out
@@ -0,0 +1,10 @@
+\set ECHO none
+1..7
+ok 1 - Create non-superuser role
+ok 2 - Non-superuser DROP SCHEMA CASCADE
+ok 3 - Non-superuser DROP OWNED BY
+ok 4 - Insert stale registration
+ok 5 - Stale registration is present
+ok 6 - Superuser DROP SCHEMA with stale registration
+ok 7 - extension_drop's schema should not be reachable via search_path
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/expected/unrelated_drops_1.out b/test/expected/unrelated_drops_1.out
new file mode 100644
index 0000000..19ec9b0
--- /dev/null
+++ b/test/expected/unrelated_drops_1.out
@@ -0,0 +1,10 @@
+\set ECHO none
+1..7
+ok 1 - Create non-superuser role
+ok 2 - Non-superuser DROP SCHEMA CASCADE
+ok 3 - Non-superuser DROP OWNED BY
+ok 4 - Insert stale registration
+ok 5 - Stale registration is present
+ok 6 - Superuser DROP SCHEMA with stale registration
+ok 7 # SKIP existing mode: extension_drop's placement is outside this suite's control
+# TRANSACTION INTENTIONALLY LEFT OPEN!
diff --git a/test/helpers/test_ext__verify_dropped.sql b/test/helpers/test_ext__verify_dropped.sql
new file mode 100644
index 0000000..a86f134
--- /dev/null
+++ b/test/helpers/test_ext__verify_dropped.sql
@@ -0,0 +1,11 @@
+SELECT hasnt_extension('extension_drop_test', 'Test extension does not exist');
+SELECT is_empty(
+  $$SELECT * FROM $$ || :'TT'
+  , :'TT' || ' is empty'
+);
+SELECT is_empty(
+  format($$SELECT unnest(%I.extension_drop__sanity_check())$$, :'extension_drop_schema')
+  , 'No stale registration'
+);
+
+-- vi: expandtab sw=2 ts=2
diff --git a/test/sql/drop_denied.sql b/test/sql/drop_denied.sql
new file mode 100644
index 0000000..ac3af46
--- /dev/null
+++ b/test/sql/drop_denied.sql
@@ -0,0 +1,378 @@
+\set ECHO none
+\i test/pgxntool/setup.sql
+
+/*
+ * Dropping an extension that is registered with extension_drop needs access to
+ * extension_drop's registration table; without it the caller must get an actionable
+ * insufficient_privilege error, not a raw "permission denied for table". Dropping an
+ * unregistered extension needs no grants at all, but a stale registration still fails.
+ * Covers the three commands the trigger fires for.
+ */
+SELECT plan(
+  2 -- Setup: role, schema with extension
+  + 1 -- DROP SCHEMA CASCADE without USAGE on extension_drop's schema
+  + 3 -- DETAIL and HINT
+  + 2 -- USAGE on extension_drop's schema, but no table privileges
+  + 2 -- DETAIL
+  + 2 -- SELECT but not DELETE
+  + 2 -- SELECT and DELETE, registered SQL fails with its own privilege error
+  + 4 -- SELECT and DELETE, registered SQL succeeds
+  + 1 -- Registration removed
+  + 4 -- The same privileges held through a group role
+  + 3 -- Unregistered, no USAGE: recreate, unregister, DROP SCHEMA CASCADE
+  + 2 -- Unregistered, USAGE only: DROP SCHEMA CASCADE
+  + 3 -- Unregistered, USAGE only: DROP OWNED BY
+  + 5 -- Unregistered, SELECT but not DELETE
+  + 6 -- Helper not executable: falls through to the caller's DELETE
+  + 4 -- Temp table shadowing extension_drop__commands
+  + 6 -- Stale registration
+  + 4 -- DROP EXTENSION by a role that was a superuser when it created it
+  + 3 -- DROP EXTENSION of an unregistered extension by that role
+  + 1 -- extension_drop's schema should not be on search_path (test/finish.sql)
+);
+
+-- Hide version-specific NOTICE/WARNING text from the drops
+SET client_min_messages = ERROR;
+
+\set DROP_SCHEMA 'DO $$ BEGIN SET LOCAL ROLE extension_drop_test_plain; DROP SCHEMA extension_drop_test_plain_schema CASCADE; RESET ROLE; END $$'
+\set DROP_OWNED 'DO $$ BEGIN SET LOCAL ROLE extension_drop_test_plain; DROP OWNED BY extension_drop_test_plain CASCADE; RESET ROLE; END $$'
+\set RECREATE 'CREATE SCHEMA extension_drop_test_plain_schema AUTHORIZATION extension_drop_test_plain; CREATE EXTENSION extension_drop_test SCHEMA extension_drop_test_plain_schema'
+\set UNREGISTER 'SELECT ' :"extension_drop_schema" '.extension_drop__remove(''extension_drop_test'')'
+
+-- The primary message names the table, its owner and the extensions being dropped
+SELECT format(
+  'permission denied for table "%s"."extension_drop__commands" (owned by role "%s"), which extension_drop needs to drop extension(s) extension_drop_test'
+  , :'extension_drop_schema'
+  , (SELECT pg_get_userbyid(relowner) FROM pg_class WHERE oid = format('%I.extension_drop__commands', :'extension_drop_schema')::regclass)
+) AS "MSG" \gset
+
+SELECT lives_ok(
+  'CREATE ROLE extension_drop_test_plain'
+  , 'Create non-superuser role'
+);
+-- Created as superuser, so the role only owns the schema
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Create schema owned by role containing a registered extension'
+);
+
+SELECT throws_ok(
+  :'DROP_SCHEMA'
+  , '42501'
+  , :'MSG'
+  , 'Registered: DROP SCHEMA CASCADE without USAGE on extension_drop''s schema'
+);
+
+-- The error text reaches the caller as DETAIL and HINT; stash them in GUCs to compare
+SELECT lives_ok(
+  $q$DO $$
+  DECLARE d text; h text;
+  BEGIN
+    SET LOCAL ROLE extension_drop_test_plain;
+    DROP SCHEMA extension_drop_test_plain_schema CASCADE;
+  EXCEPTION WHEN insufficient_privilege THEN
+    GET STACKED DIAGNOSTICS d = PG_EXCEPTION_DETAIL, h = PG_EXCEPTION_HINT;
+    PERFORM set_config('extension_drop_test.detail', d, false), set_config('extension_drop_test.hint', h, false);
+  END $$$q$
+  , 'Capture DETAIL and HINT'
+);
+/*
+ * Without USAGE the table can't be found by name ("does not exist"); in existing mode the schema is
+ * public, which everyone can use, so it is "permission denied" instead.
+ */
+SELECT matches(
+  current_setting('extension_drop_test.detail')
+  , '^(relation "extension_drop__commands" does not exist|permission denied for table extension_drop__commands)$'
+  , 'DETAIL'
+);
+SELECT is(
+  current_setting('extension_drop_test.hint')
+  , format(
+      'Run the drop as role %1$I or a superuser, or grant USAGE on schema %2$I and SELECT, DELETE on %2$I.extension_drop__commands to the current role.'
+      , current_user, :'extension_drop_schema')
+  , 'HINT'
+);
+
+SELECT lives_ok(
+  format('GRANT USAGE ON SCHEMA %I TO extension_drop_test_plain', :'extension_drop_schema')
+  , 'Grant USAGE on extension_drop''s schema'
+);
+SELECT throws_ok(
+  :'DROP_SCHEMA'
+  , '42501'
+  , :'MSG'
+  , 'Registered: DROP SCHEMA CASCADE with USAGE but no table privileges'
+);
+SELECT lives_ok(
+  $q$DO $$
+  DECLARE d text;
+  BEGIN
+    SET LOCAL ROLE extension_drop_test_plain;
+    DROP SCHEMA extension_drop_test_plain_schema CASCADE;
+  EXCEPTION WHEN insufficient_privilege THEN
+    GET STACKED DIAGNOSTICS d = PG_EXCEPTION_DETAIL;
+    PERFORM set_config('extension_drop_test.detail', d, false);
+  END $$$q$
+  , 'Capture DETAIL'
+);
+SELECT is(
+  current_setting('extension_drop_test.detail')
+  , 'permission denied for table extension_drop__commands'
+  , 'DETAIL is the original error'
+);
+
+-- SELECT alone is not enough for a registered extension: the trigger deletes the registration
+SELECT lives_ok(
+  format('GRANT SELECT ON %I.extension_drop__commands TO extension_drop_test_plain', :'extension_drop_schema')
+  , 'Grant SELECT'
+);
+SELECT throws_ok(
+  :'DROP_SCHEMA'
+  , '42501'
+  , :'MSG'
+  , 'Registered: DROP SCHEMA CASCADE with SELECT but not DELETE'
+);
+
+-- A privilege error from the registered SQL itself is not extension_drop's to translate
+SELECT lives_ok(
+  format($$GRANT DELETE ON %1$I.extension_drop__commands TO extension_drop_test_plain;
+           SELECT %1$I.extension_drop__update('extension_drop_test', 'CREATE ROLE extension_drop_test_never')$$
+    , :'extension_drop_schema')
+  , 'Grant DELETE, register SQL that needs CREATEROLE'
+);
+SELECT throws_ok(
+  :'DROP_SCHEMA'
+  , '42501'
+  , 'permission denied to create role'
+  , 'Registered SQL''s own privilege error surfaces unchanged'
+);
+
+SELECT lives_ok(
+  format($$SELECT %I.extension_drop__update('extension_drop_test', 'SELECT 1')$$, :'extension_drop_schema')
+  , 'Register harmless SQL'
+);
+SELECT lives_ok(
+  :'DROP_SCHEMA'
+  , 'Registered: DROP SCHEMA CASCADE with the privileges the HINT names'
+);
+SELECT is_empty(
+  format($$SELECT unnest(%I.extension_drop__sanity_check())$$, :'extension_drop_schema')
+  , 'No stale registration'
+);
+SELECT is_empty(
+  format($$SELECT 1 FROM %I.extension_drop__commands WHERE extension_name = 'extension_drop_test'$$, :'extension_drop_schema')
+  , 'Registration removed'
+);
+
+-- Privileges held only through a group role the caller is a member of
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Recreate the registered extension'
+);
+SELECT lives_ok(
+  format(
+    $$SELECT %1$I.extension_drop__update('extension_drop_test', 'SELECT 1');
+      REVOKE SELECT, DELETE ON %1$I.extension_drop__commands FROM extension_drop_test_plain;
+      REVOKE USAGE ON SCHEMA %1$I FROM extension_drop_test_plain;
+      CREATE ROLE extension_drop_test_group;
+      GRANT USAGE ON SCHEMA %1$I TO extension_drop_test_group;
+      GRANT SELECT, DELETE ON %1$I.extension_drop__commands TO extension_drop_test_group;
+      GRANT extension_drop_test_group TO extension_drop_test_plain$$
+    , :'extension_drop_schema')
+  , 'Move the grants from the role to a group it belongs to'
+);
+SELECT lives_ok(
+  :'DROP_SCHEMA'
+  , 'Registered: DROP SCHEMA CASCADE with the privileges held through a group role'
+);
+SELECT lives_ok(
+  'REVOKE extension_drop_test_group FROM extension_drop_test_plain'
+  , 'Remove all of the role''s access'
+);
+
+-- Unregistered extensions need no grants, but still need to be findable: no USAGE means the helper isn't
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Recreate the extension'
+);
+SELECT lives_ok(
+  :'UNREGISTER'
+  , 'Unregister the extension'
+);
+-- In existing mode extension_drop is in public, which every role can use, so there is no "no USAGE" case
+SELECT has_schema_privilege('extension_drop_test_plain', :'extension_drop_schema', 'USAGE') AS plain_has_usage \gset
+\if :plain_has_usage
+  SELECT skip('existing mode: the role can use extension_drop''s schema', 1);
+\else
+  SELECT throws_ok(
+    :'DROP_SCHEMA'
+    , '42501'
+    , :'MSG'
+    , 'Unregistered: DROP SCHEMA CASCADE without USAGE on extension_drop''s schema'
+  );
+\endif
+
+SELECT lives_ok(
+  format('GRANT USAGE ON SCHEMA %I TO extension_drop_test_plain', :'extension_drop_schema')
+  , 'Grant USAGE on extension_drop''s schema'
+);
+SELECT lives_ok(
+  :'DROP_SCHEMA'
+  , 'Unregistered: DROP SCHEMA CASCADE with USAGE but no table privileges'
+);
+
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Recreate the extension'
+);
+SELECT lives_ok(
+  :'UNREGISTER'
+  , 'Unregister the extension'
+);
+SELECT lives_ok(
+  :'DROP_OWNED'
+  , 'Unregistered: DROP OWNED BY with USAGE but no table privileges'
+);
+
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Recreate the extension'
+);
+SELECT lives_ok(
+  :'UNREGISTER'
+  , 'Unregister the extension'
+);
+SELECT lives_ok(
+  format('GRANT SELECT ON %I.extension_drop__commands TO extension_drop_test_plain', :'extension_drop_schema')
+  , 'Grant SELECT'
+);
+SELECT lives_ok(
+  :'DROP_SCHEMA'
+  , 'Unregistered: DROP SCHEMA CASCADE with SELECT but not DELETE'
+);
+SELECT lives_ok(
+  format('REVOKE SELECT ON %I.extension_drop__commands FROM extension_drop_test_plain', :'extension_drop_schema')
+  , 'Revoke SELECT'
+);
+
+-- With EXECUTE on the helper revoked, the trigger falls through to the caller's own DELETE
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Recreate the extension'
+);
+SELECT lives_ok(
+  :'UNREGISTER'
+  , 'Unregister the extension'
+);
+SELECT lives_ok(
+  format('REVOKE EXECUTE ON FUNCTION %I.extension_drop__registered(name[]) FROM PUBLIC', :'extension_drop_schema')
+  , 'Revoke EXECUTE on the helper'
+);
+SELECT throws_ok(
+  :'DROP_SCHEMA'
+  , '42501'
+  , :'MSG'
+  , 'Unregistered: DROP SCHEMA CASCADE without EXECUTE on the helper or table privileges'
+);
+SELECT lives_ok(
+  format('GRANT EXECUTE ON FUNCTION %I.extension_drop__registered(name[]) TO PUBLIC', :'extension_drop_schema')
+  , 'Restore EXECUTE on the helper'
+);
+SELECT lives_ok(
+  'DROP SCHEMA extension_drop_test_plain_schema CASCADE'
+  , 'Superuser drop schema'
+);
+
+-- A temp table named like ours must not hide the real registration from the helper
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Recreate the registered extension'
+);
+SELECT throws_ok(
+  $q$DO $$
+  BEGIN
+    SET LOCAL ROLE extension_drop_test_plain;
+    CREATE TEMP TABLE extension_drop__commands(extension_name name, sql text);
+    DROP SCHEMA extension_drop_test_plain_schema CASCADE;
+  END $$$q$
+  , '42501'
+  , :'MSG'
+  , 'Registered extension is still found when the caller has a temp table of the same name'
+);
+SELECT lives_ok(
+  :'UNREGISTER'
+  , 'Unregister the extension'
+);
+SELECT lives_ok(
+  'DROP SCHEMA extension_drop_test_plain_schema CASCADE'
+  , 'Superuser drop schema'
+);
+
+-- A stale registration must still fail the drop of an unregistered extension
+SELECT lives_ok(
+  :'RECREATE'
+  , 'Recreate the extension'
+);
+SELECT lives_ok(
+  :'UNREGISTER'
+  , 'Unregister the extension'
+);
+SELECT lives_ok(
+  format($$INSERT INTO %I.extension_drop__commands VALUES('extension_drop_test_stale', 'SELECT 1')$$, :'extension_drop_schema')
+  , 'Insert a stale registration'
+);
+SELECT throws_ok(
+  :'DROP_SCHEMA'
+  , 'XD001'
+  , 'unexpected drop commands'
+  , 'Unregistered: DROP SCHEMA CASCADE with a stale registration present'
+);
+SELECT lives_ok(
+  format('SELECT %I.extension_drop__repair()', :'extension_drop_schema')
+  , 'Repair'
+);
+SELECT lives_ok(
+  'DROP SCHEMA extension_drop_test_plain_schema CASCADE'
+  , 'Superuser drop schema'
+);
+
+-- ALTER EXTENSION can't change the owner, so create it as a role that is then demoted
+SELECT lives_ok(
+  'CREATE ROLE extension_drop_test_owner SUPERUSER'
+  , 'Create role'
+);
+SELECT lives_ok(
+  $q$DO $$ BEGIN SET LOCAL ROLE extension_drop_test_owner; CREATE EXTENSION extension_drop_test; RESET ROLE; END $$$q$
+  , 'Create test extension as role'
+);
+SELECT lives_ok(
+  'ALTER ROLE extension_drop_test_owner NOSUPERUSER'
+  , 'Demote role'
+);
+SELECT throws_ok(
+  $q$DO $$ BEGIN SET LOCAL ROLE extension_drop_test_owner; DROP EXTENSION extension_drop_test; END $$$q$
+  , '42501'
+  , :'MSG'
+  , 'DROP EXTENSION by the extension''s non-superuser owner'
+);
+
+SELECT lives_ok(
+  :'UNREGISTER'
+  , 'Unregister the extension'
+);
+SELECT lives_ok(
+  format('GRANT USAGE ON SCHEMA %I TO extension_drop_test_owner', :'extension_drop_schema')
+  , 'Grant USAGE on extension_drop''s schema'
+);
+SELECT lives_ok(
+  $q$DO $$ BEGIN SET LOCAL ROLE extension_drop_test_owner; DROP EXTENSION extension_drop_test; RESET ROLE; END $$$q$
+  , 'Unregistered: DROP EXTENSION by the extension''s non-superuser owner with USAGE but no table privileges'
+);
+SELECT is_empty(
+  format($$SELECT unnest(%I.extension_drop__sanity_check())$$, :'extension_drop_schema')
+  , 'No stale registration'
+);
+
+\i test/finish.sql
+
+-- vi: expandtab sw=2 ts=2
diff --git a/test/sql/drop_owned.sql b/test/sql/drop_owned.sql
new file mode 100644
index 0000000..495ee04
--- /dev/null
+++ b/test/sql/drop_owned.sql
@@ -0,0 +1,48 @@
+\set ECHO none
+\i test/pgxntool/setup.sql
+
+/*
+ * DROP OWNED BY can drop an extension; its registered command must run and
+ * the registration must go away, or the stale row makes every later DROP
+ * EXTENSION fail.
+ */
+SELECT plan(
+  1 -- test/helpers/test_ext__insert.sql
+  + 4 -- DROP OWNED BY drops the extension
+  + 3 -- test/helpers/test_ext__verify_dropped.sql
+  + 4 -- test/helpers/test_ext__create_drop.sql
+  + 1 -- extension_drop's schema should not be on search_path (test/finish.sql)
+);
+
+\i test/helpers/test_ext__insert.sql
+
+SELECT lives_ok(
+  'CREATE ROLE extension_drop_test_owner SUPERUSER'
+  , 'Create role'
+);
+-- ALTER EXTENSION can't change the owner, so create it as that role
+SELECT lives_ok(
+  $q$DO $$ BEGIN
+    SET LOCAL ROLE extension_drop_test_owner;
+    CREATE EXTENSION extension_drop_test;
+    RESET ROLE;
+  END $$$q$
+  , 'Create test extension as role'
+);
+SELECT bag_eq(
+  format($$SELECT * FROM %I.extension_drop__get('extension_drop_test')$$, :'extension_drop_schema')
+  , $$SELECT 'extension_drop_test'::name, 'DELETE FROM extension_drop_test_table'::text$$
+  , 'Verify extension_drop__get()'
+);
+
+SELECT lives_ok(
+  'DROP OWNED BY extension_drop_test_owner'
+  , 'Drop owned'
+);
+\i test/helpers/test_ext__verify_dropped.sql
+
+\i test/helpers/test_ext__create_drop.sql
+
+\i test/finish.sql
+
+-- vi: expandtab sw=2 ts=2
diff --git a/test/sql/drop_schema_cascade.sql b/test/sql/drop_schema_cascade.sql
new file mode 100644
index 0000000..2cec30d
--- /dev/null
+++ b/test/sql/drop_schema_cascade.sql
@@ -0,0 +1,46 @@
+\set ECHO none
+\i test/pgxntool/setup.sql
+
+/*
+ * DROP SCHEMA ... CASCADE can drop an extension; its registered command must
+ * run and the registration must go away, or the stale row makes every later
+ * DROP EXTENSION fail.
+ */
+SELECT plan(
+  1 -- test/helpers/test_ext__insert.sql
+  + 4 -- DROP SCHEMA CASCADE drops the extension
+  + 3 -- test/helpers/test_ext__verify_dropped.sql
+  + 4 -- test/helpers/test_ext__create_drop.sql
+  + 1 -- extension_drop's schema should not be on search_path (test/finish.sql)
+);
+
+-- Hide the version-specific "drop cascades to" NOTICE
+SET client_min_messages = WARNING;
+
+\i test/helpers/test_ext__insert.sql
+
+SELECT lives_ok(
+  'CREATE SCHEMA extension_drop_test_schema'
+  , 'Create schema'
+);
+SELECT lives_ok(
+  'CREATE EXTENSION extension_drop_test SCHEMA extension_drop_test_schema'
+  , 'Create test extension in schema'
+);
+SELECT bag_eq(
+  format($$SELECT * FROM %I.extension_drop__get('extension_drop_test')$$, :'extension_drop_schema')
+  , $$SELECT 'extension_drop_test'::name, 'DELETE FROM extension_drop_test_table'::text$$
+  , 'Verify extension_drop__get()'
+);
+
+SELECT lives_ok(
+  'DROP SCHEMA extension_drop_test_schema CASCADE'
+  , 'Drop schema cascade'
+);
+\i test/helpers/test_ext__verify_dropped.sql
+
+\i test/helpers/test_ext__create_drop.sql
+
+\i test/finish.sql
+
+-- vi: expandtab sw=2 ts=2
diff --git a/test/sql/unrelated_drops.sql b/test/sql/unrelated_drops.sql
new file mode 100644
index 0000000..e6a3515
--- /dev/null
+++ b/test/sql/unrelated_drops.sql
@@ -0,0 +1,64 @@
+\set ECHO none
+\i test/pgxntool/setup.sql
+
+/*
+ * DROP SCHEMA and DROP OWNED fire extension_drop's event trigger, so drops
+ * that involve no extension must not depend on the caller's privileges or on
+ * the state of extension_drop__commands.
+ */
+SELECT plan(
+  3 -- Non-superuser drops
+  + 3 -- Stale registration
+  + 1 -- extension_drop's schema should not be on search_path (test/finish.sql)
+);
+
+-- Hide version- and database-specific NOTICE/WARNING text from the drops
+SET client_min_messages = ERROR;
+
+SELECT lives_ok(
+  'CREATE ROLE extension_drop_test_plain'
+  , 'Create non-superuser role'
+);
+
+/*
+ * Schemas are created as superuser but owned by the role, so it needs no
+ * CREATE privilege on the database.
+ */
+SELECT lives_ok(
+  $q$DO $$ BEGIN
+    CREATE SCHEMA extension_drop_test_plain_schema AUTHORIZATION extension_drop_test_plain
+      CREATE TABLE t(i int);
+    SET LOCAL ROLE extension_drop_test_plain;
+    DROP SCHEMA extension_drop_test_plain_schema CASCADE;
+    RESET ROLE;
+  END $$$q$
+  , 'Non-superuser DROP SCHEMA CASCADE'
+);
+SELECT lives_ok(
+  $q$DO $$ BEGIN
+    CREATE SCHEMA extension_drop_test_plain_schema AUTHORIZATION extension_drop_test_plain
+      CREATE TABLE t(i int);
+    SET LOCAL ROLE extension_drop_test_plain;
+    DROP OWNED BY extension_drop_test_plain;
+    RESET ROLE;
+  END $$$q$
+  , 'Non-superuser DROP OWNED BY'
+);
+
+SELECT lives_ok(
+  format($$INSERT INTO %I.extension_drop__commands VALUES('extension_drop_test_stale', 'SELECT 1')$$, :'extension_drop_schema')
+  , 'Insert stale registration'
+);
+SELECT results_eq(
+  format($$SELECT %I.extension_drop__sanity_check()$$, :'extension_drop_schema')
+  , $$SELECT '{extension_drop_test_stale}'::name[]$$
+  , 'Stale registration is present'
+);
+SELECT lives_ok(
+  $$CREATE SCHEMA extension_drop_test_su_schema; DROP SCHEMA extension_drop_test_su_schema$$
+  , 'Superuser DROP SCHEMA with stale registration'
+);
+
+\i test/finish.sql
+
+-- vi: expandtab sw=2 ts=2