diff --git a/manticore/manticore.py b/manticore/manticore.py
index e9e1f12..5d07171 100644
--- a/manticore/manticore.py
+++ b/manticore/manticore.py
@@ -656,7 +656,7 @@ class Manticore(object):
                     f.write(fmt.format(m[1]))
                     
         if self.memory_errors_file is not None:
-            with open(args.errorfile, "w") as f:
+            with open(self._args.errorfile, "w") as f:
                 fmt = "0x{:016x}\n"
                 for m in self._executor.errors:
                     f.write(fmt.format(m))