diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
index 4df1f6ced09f..7f7cae8d4a0d 100644
--- a/lib/matplotlib/__init__.py
+++ b/lib/matplotlib/__init__.py
@@ -106,8 +106,8 @@
 import sys
 import distutils.version
 
-__version__  = '1.4.x'
-__version__numpy__ = '1.6' # minimum required numpy version
+__version__  = str('1.4.x')
+__version__numpy__ = str('1.6') # minimum required numpy version
 
 try:
     import dateutil