diff --git a/extensions/amp-bind/0.1/bind-impl.js b/extensions/amp-bind/0.1/bind-impl.js
index a688e645a2551..46b2c2392b93a 100644
--- a/extensions/amp-bind/0.1/bind-impl.js
+++ b/extensions/amp-bind/0.1/bind-impl.js
@@ -1024,7 +1024,7 @@ export class Bind {
     }
 
     if (!match) {
-      user().warn(`${TAG}: ` +
+      user().warn(TAG,
         `Default value for <${tagName} [${property}]="${expressionString}"> ` +
         `does not match first result (${expectedValue}). We recommend ` +
         'writing expressions with matching default values, but this can be ' +