Loosen argparse version requirements to avoid external package problem

1 files changed, 1 insertions, 1 deletions

diff --git a/setup.py b/setup.py
index 6c4f782..bb19af6 100644
--- a/setup.py
+++ b/setup.py
@@ -14,7 +14,7 @@ _install_requires = [
 ]
 
 if sys.version_info[:2] <= (2, 6):
-    _install_requires.append("argparse==1.2.1")
+    _install_requires.append("argparse>=1.1,<2.0")
 
 setup(
     name='mammoth',