diff --git a/src/client/Main.ts b/src/client/Main.ts
index a204ad084..9c6572249 100644
--- a/src/client/Main.ts
+++ b/src/client/Main.ts
@@ -195,6 +195,13 @@ class Client {
       }
       const lobbyId = ctx.params.lobbyId;
 
+      if (lobbyId?.endsWith("#")) {
+        // When the cookies button is pressed, '#' is added to the url
+        // causing the page to attempt to rejoin the lobby during game play.
+        console.error("Invalid lobby ID provided");
+        return;
+      }
+
       this.joinModal.open(lobbyId);
 
       consolex.log(`joining lobby ${lobbyId}`);