diff --git a/pkgs/development/python-modules/chainmap/default.nix b/pkgs/development/python-modules/chainmap/default.nix
index c2815d876e34..eb769ed46239 100644
--- a/pkgs/development/python-modules/chainmap/default.nix
+++ b/pkgs/development/python-modules/chainmap/default.nix
@@ -2,11 +2,11 @@
 
 buildPythonPackage rec {
   pname = "chainmap";
-  version = "1.0.2";
+  version = "1.0.3";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "09h5gq43w516fqswlca0nhmd2q3v8hxq15z4wqrznfwix6ya6pa0";
+    sha256 = "e42aaa4b3e2f66102a11bfd563069704bfbfd84fdcb517b564effd736bf53cd9";
   };
 
   # Requires tox