diff --git a/mozilla/layout/style/nsStyleContext.cpp b/mozilla/layout/style/nsStyleContext.cpp
index 36f67c57142..6b26bfdc21c 100644
--- a/mozilla/layout/style/nsStyleContext.cpp
+++ b/mozilla/layout/style/nsStyleContext.cpp
@@ -308,6 +308,12 @@ nsStyleContext::GetUniqueStyleData(const nsStyleStructID& aSID)
     return nsnull;
   }
 
+  if (!result) {
+    NS_WARNING("Ran out of memory while trying to allocate memory for a unique nsStyleStruct! "
+               "Returning the non-unique data.");
+    return NS_CONST_CAST(nsStyleStruct*, current);
+  }
+
   SetStyle(aSID, result);
   mBits &= ~nsCachedStyleData::GetBitForSID(aSID);