diff --git a/packages/jupyter-ai/src/components/settings/existing-api-keys.tsx b/packages/jupyter-ai/src/components/settings/existing-api-keys.tsx
index 468f26796..b22c731b9 100644
--- a/packages/jupyter-ai/src/components/settings/existing-api-keys.tsx
+++ b/packages/jupyter-ai/src/components/settings/existing-api-keys.tsx
@@ -113,7 +113,7 @@ function ExistingApiKey(props: ExistingApiKeyProps) {
   }, [input]);
 
   const onError = useCallback(
-    emsg => {
+    (emsg: string) => {
       props.alert.show('error', emsg);
     },
     [props.alert]