diff --git a/cp-webapp/src/hooks/use-chat-stream.ts b/cp-webapp/src/hooks/use-chat-stream.ts
index de7cc74..3aeb0d3 100644
--- a/cp-webapp/src/hooks/use-chat-stream.ts
+++ b/cp-webapp/src/hooks/use-chat-stream.ts
@@ -556,6 +556,8 @@ export function useChatStream() {
         }
       } finally {
         cleanupThinking();
+        // Mark any tools still in 'started' state as 'failed' when the stream ends
+        markPendingToolsAsFailed();
         setIsStreaming(false);
         setAbortController(null);