diff --git a/src/popup.svelte b/src/popup.svelte
index b446dc45b..b70f16756 100644
--- a/src/popup.svelte
+++ b/src/popup.svelte
@@ -58,7 +58,7 @@
     config.pumlServerUrl = pumlServerUrl;
 
     if (!/^https?:\/\/.*$/.test(pumlServerUrl)) {
-      errorMessage = `${pumlServerUrl} does not match https://* or http://* `;
+      inputUrlErrorMessage = `${pumlServerUrl} does not match https://* or http://* `;
       return;
     }