diff --git a/mozilla/layout/style/nsCSSStyleSheet.cpp b/mozilla/layout/style/nsCSSStyleSheet.cpp
index 7662e66bb8e..02ccdfb8fcc 100644
--- a/mozilla/layout/style/nsCSSStyleSheet.cpp
+++ b/mozilla/layout/style/nsCSSStyleSheet.cpp
@@ -1166,9 +1166,10 @@ CloneRuleInto(nsISupports* aRule, void* aArray)
 }
 
 nsCSSStyleSheetInner::nsCSSStyleSheetInner(nsCSSStyleSheetInner& aCopy,
-                                       nsICSSStyleSheet* aParentSheet)
+                                           nsICSSStyleSheet* aParentSheet)
   : mSheets(),
     mSheetURI(aCopy.mSheetURI),
+    mOriginalSheetURI(aCopy.mOriginalSheetURI),
     mBaseURI(aCopy.mBaseURI),
     mComplete(aCopy.mComplete)
 {