diff --git a/src/documents/tests/test_views.py b/src/documents/tests/test_views.py
index 9b1724a16..1b7d953c8 100644
--- a/src/documents/tests/test_views.py
+++ b/src/documents/tests/test_views.py
@@ -356,6 +356,31 @@ class TestAISuggestions(DirectoriesMixin, TestCase):
             },
         )
 
+    @patch("documents.views.get_ai_document_classification")
+    @override_settings(
+        AI_ENABLED=True,
+        LLM_BACKEND="openai",
+    )
+    def test_suggestions_with_invalid_ai_configuration(
+        self,
+        mock_get_ai_classification,
+    ) -> None:
+        mock_get_ai_classification.side_effect = ValueError(
+            "Unknown model 'gpt-5.4-mini-2026-03-17'.",
+        )
+
+        self.client.force_login(user=self.user)
+        response = self.client.get(f"/api/documents/{self.document.pk}/suggestions/")
+
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        self.assertEqual(
+            response.json(),
+            {
+                "ai": ["Invalid AI configuration."],
+            },
+        )
+        self.assertIsNone(get_llm_suggestion_cache(self.document.pk, backend="openai"))
+
     def test_invalidate_suggestions_cache(self) -> None:
         self.client.force_login(user=self.user)
         suggestions = {
diff --git a/src/documents/views.py b/src/documents/views.py
index d4c2ccd11..a3b12fb82 100644
--- a/src/documents/views.py
+++ b/src/documents/views.py
@@ -1320,7 +1320,17 @@ class DocumentViewSet(
                 refresh_suggestions_cache(doc.pk)
                 return Response(cached_llm_suggestions.suggestions)
 
-            llm_suggestions = get_ai_document_classification(doc, request.user)
+            try:
+                llm_suggestions = get_ai_document_classification(doc, request.user)
+            except ValueError as exc:
+                logger.exception(
+                    "Invalid AI configuration while generating suggestions for "
+                    "document %s: %s",
+                    doc.pk,
+                    exc,
+                    exc_info=True,
+                )
+                raise ValidationError({"ai": [_("Invalid AI configuration.")]}) from exc
 
             matched_tags = match_tags_by_name(
                 llm_suggestions.get("tags", []),