diff --git a/mozilla/content/base/src/nsParserUtils.cpp b/mozilla/content/base/src/nsParserUtils.cpp
index 8a6be8b54fa..a23b3d79873 100644
--- a/mozilla/content/base/src/nsParserUtils.cpp
+++ b/mozilla/content/base/src/nsParserUtils.cpp
@@ -124,6 +124,9 @@ nsParserUtils::IsJavaScriptLanguage(const nsString& aName, const char* *aVersion
       aName.EqualsIgnoreCase("Mocha")) {
     version = JSVERSION_DEFAULT;
   }
+  else if (aName.EqualsIgnoreCase("JavaScript1.0")) {
+    version = JSVERSION_1_0;
+  }
   else if (aName.EqualsIgnoreCase("JavaScript1.1")) {
     version = JSVERSION_1_1;
   }