diff --git a/package.json b/package.json
index f97c8b06..fc463485 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,6 @@
     "karma-sauce-launcher": "~0.2.3",
     "grunt-checkrepo": "~0.1.0",
     "grunt-saucelabs": "~4.0.2",
-    "grunt-checkrepo": "~0.1.0",
     "grunt-git-status": "~1.0.0",
     "grunt-template": "~0.2.3",
     "source-map": "~0.1.40"
diff --git a/src/apply-preserving-inline-style.js b/src/apply-preserving-inline-style.js
index 4002a2f5..3ebd9e4d 100644
--- a/src/apply-preserving-inline-style.js
+++ b/src/apply-preserving-inline-style.js
@@ -205,6 +205,11 @@
     var animatedStyle = new AnimatedCSSStyleDeclaration(element);
     try {
       configureProperty(element, 'style', { get: function() { return animatedStyle; } });
+
+      if (!element.style._set || !element.style._clear) {
+        throw 'Couldnt configure property style.';
+      }
+
     } catch (_) {
       // iOS and older versions of Safari (pre v7) do not support overriding an element's
       // style object. Animations will clobber any inline styles as a result.