diff --git a/content/base/src/nsHTMLContentSerializer.cpp b/content/base/src/nsHTMLContentSerializer.cpp
index 875feb19753b..3e70d42ed517 100644
--- a/content/base/src/nsHTMLContentSerializer.cpp
+++ b/content/base/src/nsHTMLContentSerializer.cpp
@@ -201,12 +201,13 @@ nsHTMLContentSerializer::IsJavaScript(nsIAtom* aAttrNameAtom, const nsAString& a
 {
   if (aAttrNameAtom == nsHTMLAtoms::href
   || aAttrNameAtom == nsHTMLAtoms::src) {
-    // note that there is a problem in that if this value starts with leading spaces we won't do the right thing
-    // this is covered in bug #59604
     static const char kJavaScript[] = "javascript";
     PRInt32 pos = aValueString.FindChar(':');
-    const nsAutoString scheme(Substring(aValueString, 0, pos));
-    if ((pos == (PRInt32)(sizeof kJavaScript - 1)) &&
+    if ( pos < (PRInt32)(sizeof kJavaScript - 1) )
+        return PR_FALSE;
+    nsAutoString scheme(Substring(aValueString, 0, pos));
+    scheme.StripWhitespace();
+    if ((scheme.Length() == (sizeof kJavaScript - 1)) &&
         scheme.EqualsIgnoreCase(kJavaScript))
       return PR_TRUE;
     else