diff --git a/libs/partners/ollama/langchain_ollama/chat_models.py b/libs/partners/ollama/langchain_ollama/chat_models.py
index 890f47f39d6..c5667bec721 100644
--- a/libs/partners/ollama/langchain_ollama/chat_models.py
+++ b/libs/partners/ollama/langchain_ollama/chat_models.py
@@ -774,6 +774,11 @@ class ChatOllama(BaseChatModel):
             **kwargs,
         }
 
+        # Filter out 'strict' argument if present, as it is not supported by Ollama
+        # but may be passed by upstream libraries (e.g. LangChain ProviderStrategy)
+        if "strict" in params:
+            params.pop("strict")
+
         if tools := kwargs.get("tools"):
             params["tools"] = tools
 
diff --git a/libs/partners/ollama/tests/unit_tests/test_chat_models.py b/libs/partners/ollama/tests/unit_tests/test_chat_models.py
index 666d4877953..34413e7fe1a 100644
--- a/libs/partners/ollama/tests/unit_tests/test_chat_models.py
+++ b/libs/partners/ollama/tests/unit_tests/test_chat_models.py
@@ -410,3 +410,29 @@ def test_explicit_options_dict_preserved() -> None:
 
         # Explicit options should be preserved as-is
         assert options == {"temperature": 0.5, "custom_param": None}
+
+
+def test_chat_ollama_ignores_strict_arg() -> None:
+    """Test that ChatOllama ignores the 'strict' argument."""
+    response = [
+        {
+            "model": "test-model",
+            "created_at": "2025-01-01T00:00:00.000000000Z",
+            "done": True,
+            "done_reason": "stop",
+            "message": {"role": "assistant", "content": "Hello!"},
+        }
+    ]
+
+    with patch("langchain_ollama.chat_models.Client") as mock_client_class:
+        mock_client = MagicMock()
+        mock_client_class.return_value = mock_client
+        mock_client.chat.return_value = response
+
+        llm = ChatOllama(model="test-model")
+        # Invoke with strict=True
+        llm.invoke([HumanMessage("Hello")], strict=True)
+
+        # Check that 'strict' was NOT passed to the client
+        call_kwargs = mock_client.chat.call_args[1]
+        assert "strict" not in call_kwargs