diff --git a/pkgs/development/python-modules/acme/default.nix b/pkgs/development/python-modules/acme/default.nix
index e63a26e5f74f..97e725bb7119 100644
--- a/pkgs/development/python-modules/acme/default.nix
+++ b/pkgs/development/python-modules/acme/default.nix
@@ -10,7 +10,6 @@
 , requests-toolbelt
 , six
 , werkzeug
-, mock
 , ndg-httpsclient
 }:
 
@@ -21,7 +20,7 @@ buildPythonPackage rec {
 
   propagatedBuildInputs = [
     cryptography pyasn1 pyopenssl pyRFC3339 pytz requests requests-toolbelt six
-    werkzeug mock ndg-httpsclient josepy
+    werkzeug ndg-httpsclient josepy
   ];
 
   # does not contain any tests