diff --git a/CHANGELOG b/CHANGELOG
index 2cd155260..8fe13a643 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,6 +5,10 @@ NEXT
 
 - Fix example in monkeypatch documentation, thanks t-8ch.
 
+- Do not mark as universal wheel because Python 2.6 is different from
+  other builds due to the extra argparse dependency.  Fixes issue566.
+  Thanks sontek.
+
 2.6.1
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