diff --git a/src/ol/style/atlasmanager.js b/src/ol/style/atlasmanager.js
index 8c03c38d06..eb1683d68d 100644
--- a/src/ol/style/atlasmanager.js
+++ b/src/ol/style/atlasmanager.js
@@ -126,6 +126,7 @@ ol.style.AtlasManager.prototype.add =
       ++ii;
     }
   }
+  goog.asserts.fail();
 };