diff --git a/src/librustdoc/html/static/storage.js b/src/librustdoc/html/static/storage.js
index c55b1e414436c..ab2cf8f796d48 100644
--- a/src/librustdoc/html/static/storage.js
+++ b/src/librustdoc/html/static/storage.js
@@ -118,7 +118,8 @@ function switchTheme(styleElem, mainStyleElem, newTheme, saveTheme) {
 }
 
 function getSystemValue() {
-    return getComputedStyle(document.documentElement).getPropertyValue('content');
+    var property = getComputedStyle(document.documentElement).getPropertyValue('content');
+    return property.replace(/\"\'/g, "");
 }
 
 switchTheme(currentTheme, mainTheme,