diff --git a/bower.json b/bower.json
index e9042bf..96902a8 100644
--- a/bower.json
+++ b/bower.json
@@ -54,7 +54,7 @@
     "js-cookie": "^2.1.3",
     "list.js": "^1.2.0",
     "store-js": "store.js#^1.3.20",
-    "string": "^3.3.1",
+    "string": "~3.3.1",
     "visibilityjs": "^1.2.4",
     "pdfobject": "pdfobject2#*",
     "gist-embed": "*",