diff --git a/git/cmd.py b/git/cmd.py
index 245a7f609..a4d4c323a 100644
--- a/git/cmd.py
+++ b/git/cmd.py
@@ -580,7 +580,7 @@ def execute(self, command,
 
         stdout_sink = (PIPE
                        if with_stdout
-                       else getattr(subprocess, 'DEVNULL', open(os.devnull, 'wb')))
+                       else getattr(subprocess, 'DEVNULL', None) or open(os.devnull, 'wb'))
         log.debug("Popen(%s, cwd=%s, universal_newlines=%s, shell=%s)",
                   command, cwd, universal_newlines, shell)
         try: