diff --git a/src/firebase/data.ts b/src/firebase/data.ts
index b205407..537cf6e 100644
--- a/src/firebase/data.ts
+++ b/src/firebase/data.ts
@@ -125,12 +125,19 @@ export async function getApiKey(userId: string): Promise<string | null> {
   }
 }
 
-export async function rotateKey(userId: string): Promise<string | null> {
+interface ApiResponse {
+  apiKey: string;
+}
+
+export async function rotateKey(userId: string): Promise<string | null | void> {
   // invoke a callable function to rotate the user's api key
   // this function is defined in functions/src/index.ts
   const rotateApiKey = httpsCallable(functions, 'rotateApiKey')
   const key = rotateApiKey({ userId: userId }).then((result) => {
-    return result.data.apiKey
+    if (typeof result.data === 'object' && result.data !== null && 'apiKey' in result.data) {
+      return (result.data as ApiResponse).apiKey;
+  }
+  return undefined
   }).catch((error) => {
     console.error(error)
   }).finally(() => {
diff --git a/src/stores/apikey.ts b/src/stores/apikey.ts
index 8ff7c61..6701897 100644
--- a/src/stores/apikey.ts
+++ b/src/stores/apikey.ts
@@ -17,7 +17,7 @@ export const useApiKeyStore = defineStore('apikey', () => {
     const userId = useAuthStore().user!.uid
     rotateKeyCallable(userId).then((key) => {
       console.log('Key is now', key)
-      if (key != null) {
+      if (typeof key === 'string') {
         console.log('Rotated key to', key)
         apikey.value = key
       }