diff --git a/setup.py b/setup.py
index ac7a8625d37a91480074932e1c49d9ca7bbca5ca..ffdaf8a19ab9861b9fd2463a3db46f20e7c512a5 100644
--- a/setup.py
+++ b/setup.py
@@ -47,6 +47,7 @@ setup(name="pytools",
           "decorator>=3.2.0",
           "appdirs>=1.4.0",
           "six>=1.8.0",
+          "numpy>=1.6.0",
           ],
 
       author="Andreas Kloeckner",