diff --git a/mozilla/content/base/src/nsDocument.cpp b/mozilla/content/base/src/nsDocument.cpp
index 63159e85f1a..a867e55bf20 100644
--- a/mozilla/content/base/src/nsDocument.cpp
+++ b/mozilla/content/base/src/nsDocument.cpp
@@ -404,7 +404,7 @@ nsIStyleSheet* nsDocument::GetStyleSheetAt(PRInt32 aIndex)
 
 void nsDocument::AddStyleSheetToSet(nsIStyleSheet* aSheet, nsIStyleSet* aSet)
 {
-  aSet->AppendDocStyleSheet(aSheet);
+  aSet->InsertDocStyleSheetBefore(aSheet, nsnull);  // put it first
 }
 
 void nsDocument::AddStyleSheet(nsIStyleSheet* aSheet)
diff --git a/mozilla/layout/base/src/nsDocument.cpp b/mozilla/layout/base/src/nsDocument.cpp
index 63159e85f1a..a867e55bf20 100644
--- a/mozilla/layout/base/src/nsDocument.cpp
+++ b/mozilla/layout/base/src/nsDocument.cpp
@@ -404,7 +404,7 @@ nsIStyleSheet* nsDocument::GetStyleSheetAt(PRInt32 aIndex)
 
 void nsDocument::AddStyleSheetToSet(nsIStyleSheet* aSheet, nsIStyleSet* aSet)
 {
-  aSet->AppendDocStyleSheet(aSheet);
+  aSet->InsertDocStyleSheetBefore(aSheet, nsnull);  // put it first
 }
 
 void nsDocument::AddStyleSheet(nsIStyleSheet* aSheet)