diff --git a/src/shared/util.js b/src/shared/util.js
index 780af3388..58671f09a 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -310,6 +310,7 @@ function isValidUrl(url, allowRelative) {
     case 'https':
     case 'ftp':
     case 'mailto':
+    case 'tel':
       return true;
     default:
       return false;