diff --git a/lib/shared/id-utils.js b/lib/shared/id-utils.js
--- a/lib/shared/id-utils.js
+++ b/lib/shared/id-utils.js
@@ -155,7 +155,7 @@
 }
 
 function extractFIDFromUserID(userID: string): ?string {
-  if (!userID.includes(farcasterUserIDPrefix)) {
+  if (!userID.startsWith(farcasterUserIDPrefix)) {
     return null;
   }