diff --git a/README.md b/README.md
index 52395c22a4a53b17bb4d9e7f9e9c6f7f4ecd261e..dd19336541317bd48dd9aa3665426713c734354b 100644
--- a/README.md
+++ b/README.md
@@ -134,6 +134,15 @@ The NIFTy package is licensed under the terms of the
 *without any warranty*.
 
 
+Contributing
+------------
+
+Please note our convention not to use pure python `assert` statements in
+production code. They are not guaranteed to by executed by python and can be
+turned off by the user (`python -O` in cPython). As an alternative use
+`ift.myassert`.
+
+
 Contributors
 ------------