diff --git a/rust/src/parsing.rs b/rust/src/parsing.rs
index 374fe3cfb..4c3d967b6 100644
--- a/rust/src/parsing.rs
+++ b/rust/src/parsing.rs
@@ -833,7 +833,7 @@ impl<'a> Parser<'a> {
         iso_week: u32,
         iso_day: u32,
     ) -> Result<(u32, u32, u32), ParseError> {
-        if iso_week > 53 || iso_week > 52 && !is_long_year(iso_year as i32) {
+        if iso_week < 1 || iso_week > 53 || iso_week > 52 && !is_long_year(iso_year as i32) {
             return Err(ParseError {
                 index: self.idx,
                 message: format!(
@@ -842,7 +842,7 @@ impl<'a> Parser<'a> {
             });
         }
 
-        if iso_day > 7 {
+        if iso_day < 1 || iso_day > 7 {
             return Err(ParseError {
                 index: self.idx,
                 message: "Invalid ISO date: week day is invalid".to_string(),
diff --git a/src/pendulum/parsing/iso8601.py b/src/pendulum/parsing/iso8601.py
index c65d249e5..8684c4f22 100644
--- a/src/pendulum/parsing/iso8601.py
+++ b/src/pendulum/parsing/iso8601.py
@@ -426,10 +426,10 @@ def _get_iso_8601_week(
     year = int(year)
     week = int(week)
 
-    if week > 53 or (week > 52 and not is_long_year(year)):
+    if week < 1 or week > 53 or (week > 52 and not is_long_year(year)):
         raise ParserError("Invalid week for week date")
 
-    if weekday > 7:
+    if weekday < 1 or weekday > 7:
         raise ParserError("Invalid weekday for week date")
 
     # We can't rely on strptime directly here since
diff --git a/tests/parsing/test_parse_iso8601.py b/tests/parsing/test_parse_iso8601.py
index ed2d39887..5a82256c8 100644
--- a/tests/parsing/test_parse_iso8601.py
+++ b/tests/parsing/test_parse_iso8601.py
@@ -160,6 +160,10 @@ def test_parse_iso8601_invalid():
     # Invalid week date
     with pytest.raises(ValueError):
         parse_iso8601("2012-W63")
+    with pytest.raises(ValueError):
+        parse_iso8601("2015-W00")
+    with pytest.raises(ValueError):
+        parse_iso8601("2015-W01-0")
     with pytest.raises(ValueError):
         parse_iso8601("2012-W12-9")
     with pytest.raises(ValueError):