diff --git a/dom/src/base/nsDOMClassInfo.cpp b/dom/src/base/nsDOMClassInfo.cpp
index 037b421b1cfe..93764500751e 100644
--- a/dom/src/base/nsDOMClassInfo.cpp
+++ b/dom/src/base/nsDOMClassInfo.cpp
@@ -827,6 +827,8 @@ JSString *nsDOMClassInfo::sOnpaint_id         = nsnull;
 JSString *nsDOMClassInfo::sOnresize_id        = nsnull;
 JSString *nsDOMClassInfo::sOnscroll_id        = nsnull;
 JSString *nsDOMClassInfo::sScrollIntoView_id  = nsnull;
+JSString *nsDOMClassInfo::sScrollX_id         = nsnull;
+JSString *nsDOMClassInfo::sScrollY_id         = nsnull;
 JSString *nsDOMClassInfo::sOpen_id            = nsnull;
 JSString *nsDOMClassInfo::sItem_id            = nsnull;
 JSString *nsDOMClassInfo::sEnumerate_id       = nsnull;
@@ -898,6 +900,8 @@ nsDOMClassInfo::DefineStaticJSStrings(JSContext *cx)
   sOnresize_id       = ::JS_InternString(cx, "onresize");
   sOnscroll_id       = ::JS_InternString(cx, "onscroll");
   sScrollIntoView_id = ::JS_InternString(cx, "scrollIntoView");
+  sScrollX_id        = ::JS_InternString(cx, "scrollX");
+  sScrollY_id        = ::JS_InternString(cx, "scrollY");
   sOpen_id           = ::JS_InternString(cx, "open");
   sItem_id           = ::JS_InternString(cx, "item");
   sEnumerate_id      = ::JS_InternString(cx, "enumerateProperties");
@@ -2627,6 +2631,8 @@ nsDOMClassInfo::ShutDown()
   sOnresize_id        = jsnullstring;
   sOnscroll_id        = jsnullstring;
   sScrollIntoView_id  = jsnullstring;
+  sScrollX_id         = jsnullstring;
+  sScrollY_id         = jsnullstring;
   sOpen_id            = jsnullstring;
   sItem_id            = jsnullstring;
   sEnumerate_id       = jsnullstring;
diff --git a/dom/src/base/nsDOMClassInfo.h b/dom/src/base/nsDOMClassInfo.h
index fdbcb3f69007..10f1448ba183 100644
--- a/dom/src/base/nsDOMClassInfo.h
+++ b/dom/src/base/nsDOMClassInfo.h
@@ -153,6 +153,8 @@ protected:
             str == sStatusbar_id    ||
             str == sDirectories_id  ||
             str == sControllers_id  ||
+            str == sScrollX_id      ||
+            str == sScrollY_id      ||
             str == sLength_id);
   }
 
@@ -225,6 +227,8 @@ protected:
   static JSString *sOnresize_id;
   static JSString *sOnscroll_id;
   static JSString *sScrollIntoView_id;
+  static JSString *sScrollX_id;
+  static JSString *sScrollY_id;
   static JSString *sOpen_id;
   static JSString *sItem_id;
   static JSString *sEnumerate_id;