diff --git a/INSTALL b/INSTALL
index f96f230a79cc..d44ec5048b15 100644
--- a/INSTALL
+++ b/INSTALL
@@ -192,7 +192,7 @@ Required Dependencies
     using pip, easy_install or installing from source, the installer
     will attempt to download and install `pyparsing` from PyPI.
 
-six 1.3 or later
+six 1.4 or later
     Python 2/3 compatibility library.  This is also a dependency of
     :term:`dateutil`.
 
diff --git a/setupext.py b/setupext.py
index 92fabd255e5b..43ba888d9b0c 100755
--- a/setupext.py
+++ b/setupext.py
@@ -1179,7 +1179,7 @@ def get_extension(self):
 
 class Six(SetupPackage):
     name = "six"
-    min_version = "1.3"
+    min_version = "1.4"
 
     def check(self):
         try: