diff --git a/agent/core/llm.py b/agent/core/llm.py
index 92256e5..168e1d7 100644
--- a/agent/core/llm.py
+++ b/agent/core/llm.py
@@ -204,6 +204,7 @@ def chat(
             return self._stream_chat(data, timeout=timeout)
 
         result = self._request("/api/chat", data, timeout=timeout)
+        self._validate_response(result, ["done"])
         self._validate_message_structure(result)
         return result
 
diff --git a/tests/test_llm.py b/tests/test_llm.py
index 13fddb0..bfaf844 100644
--- a/tests/test_llm.py
+++ b/tests/test_llm.py
@@ -88,14 +88,22 @@ def test_chat_accepts_tool_call_only_response(self):
             "message": {
                 "role": "assistant",
                 "tool_calls": [{"function": {"name": "read_file", "arguments": {}}}],
-            }
+            },
+            "done": True,
         }
         with patch.object(client, "_request", return_value=response):
             self.assertEqual(client.chat([{"role": "user", "content": "hi"}]), response)
 
     def test_chat_rejects_non_dict_message(self):
         client = make_client()
-        with patch.object(client, "_request", return_value={"message": None}):
+        with patch.object(client, "_request", return_value={"message": None, "done": True}):
+            with self.assertRaises(OllamaError):
+                client.chat([{"role": "user", "content": "hi"}])
+
+    def test_chat_rejects_response_missing_done(self):
+        client = make_client()
+        response = {"message": {"role": "assistant", "content": "hi"}}
+        with patch.object(client, "_request", return_value=response):
             with self.assertRaises(OllamaError):
                 client.chat([{"role": "user", "content": "hi"}])