diff --git a/pkgs/development/python-modules/nbdime/default.nix b/pkgs/development/python-modules/nbdime/default.nix
index 1c1e52b5a79..66e1edd9390 100644
--- a/pkgs/development/python-modules/nbdime/default.nix
+++ b/pkgs/development/python-modules/nbdime/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildPythonPackage, fetchPypi, callPackage, isPy3k
+{ lib, buildPythonPackage, fetchPypi, isPy3k
 , hypothesis
 , setuptools_scm
 , six