diff --git a/src/common/filefn.cpp b/src/common/filefn.cpp
index b1d98afaf8..a05b15e438 100644
--- a/src/common/filefn.cpp
+++ b/src/common/filefn.cpp
@@ -842,6 +842,9 @@ wxString wxMacFSRefToPath( const FSRef *fsRef , CFStringRef additionalPathCompon
 {
     CFURLRef fullURLRef;
     fullURLRef = CFURLCreateFromFSRef(NULL, fsRef);
+    if ( fullURLRef == NULL)
+        return wxEmptyString;
+    
     if ( additionalPathComponent )
     {
         CFURLRef parentURLRef = fullURLRef ;