diff --git a/mozilla/xpfe/components/directory/nsDirectoryViewer.cpp b/mozilla/xpfe/components/directory/nsDirectoryViewer.cpp
index 424356aab9a..fdb6f61435e 100644
--- a/mozilla/xpfe/components/directory/nsDirectoryViewer.cpp
+++ b/mozilla/xpfe/components/directory/nsDirectoryViewer.cpp
@@ -806,7 +806,7 @@ nsHTTPIndex::Init(nsIURI* aBaseURL)
   rv = aBaseURL->GetSpec(getter_Copies(url));
   if (NS_FAILED(rv)) return rv;
 
-  mBaseURL = url;
+  mBaseURL.Assign(url);
 
   static NS_DEFINE_CID(kRDFInMemoryDataSourceCID, NS_RDFINMEMORYDATASOURCE_CID);
   rv = nsComponentManager::CreateInstance(kRDFInMemoryDataSourceCID, nsnull,
diff --git a/mozilla/xpfe/components/regviewer/nsRegistryDataSource.cpp b/mozilla/xpfe/components/regviewer/nsRegistryDataSource.cpp
index 5c32617d99f..8ddc8745be9 100644
--- a/mozilla/xpfe/components/regviewer/nsRegistryDataSource.cpp
+++ b/mozilla/xpfe/components/regviewer/nsRegistryDataSource.cpp
@@ -776,7 +776,7 @@ nsRegistryDataSource::SubkeyEnumerator::ConvertRegistryNodeToResource(nsISupport
 
     nsCAutoString newURI(rootURI);
     if (newURI.Last() != '/') newURI += '/';
-    newURI += path;
+    newURI.Append(path);
 
     rv = gRDF->GetResource(newURI, aResult);
     if (NS_FAILED(rv)) return rv;