diff --git a/pkgs/development/python-modules/traittypes/default.nix b/pkgs/development/python-modules/traittypes/default.nix
index 3fa2ad886cd4..13d2363b4000 100644
--- a/pkgs/development/python-modules/traittypes/default.nix
+++ b/pkgs/development/python-modules/traittypes/default.nix
@@ -18,7 +18,7 @@ buildPythonPackage rec {
   src = fetchFromGitHub {
     owner = "jupyter-widgets";
     repo = "traittypes";
-    rev = version;
+    tag = version;
     hash = "sha256-RwEZs4QFK+IrPFPBI7+jnQSFQryQFzEbrnOF8OyExuk=";
   };