diff --git a/layout/base/nsDocumentViewer.cpp b/layout/base/nsDocumentViewer.cpp
index 82f53e45fbf..2e9e5a71e55 100644
--- a/layout/base/nsDocumentViewer.cpp
+++ b/layout/base/nsDocumentViewer.cpp
@@ -2158,7 +2158,7 @@ DocumentViewerImpl::CreateStyleSet(nsIDocument* aDocument,
           if (!uri) continue;
 
           cssLoader->LoadSheetSync(uri, getter_AddRefs(csssheet));
-          if (!sheet) continue;
+          if (!csssheet) continue;
 
           styleSet->PrependStyleSheet(nsStyleSet::eAgentSheet, csssheet);
           shouldOverride = PR_TRUE;