diff --git a/tests/modules/programs/gpg/mutable-keyfiles.nix b/tests/modules/programs/gpg/mutable-keyfiles.nix
index 588c90704..d2028e4b4 100644
--- a/tests/modules/programs/gpg/mutable-keyfiles.nix
+++ b/tests/modules/programs/gpg/mutable-keyfiles.nix
@@ -14,6 +14,7 @@
   };
 
   test.stubs.gnupg = { };
+  test.stubs.systemd = { }; # depends on gnupg.override
 
   nmt.script = ''
     assertFileContains activate "export GNUPGHOME='/home/hm-user/.gnupg'"
diff --git a/tests/modules/services/gpg-agent/default-homedir.nix b/tests/modules/services/gpg-agent/default-homedir.nix
index faf153749..9e21eb6db 100644
--- a/tests/modules/services/gpg-agent/default-homedir.nix
+++ b/tests/modules/services/gpg-agent/default-homedir.nix
@@ -9,6 +9,7 @@ with lib;
     programs.gpg.enable = true;
 
     test.stubs.gnupg = { };
+    test.stubs.systemd = { }; # depends on gnupg.override
 
     nmt.script = ''
       in="${config.systemd.user.sockets.gpg-agent.Socket.ListenStream}"
diff --git a/tests/modules/services/gpg-agent/override-homedir.nix b/tests/modules/services/gpg-agent/override-homedir.nix
index 23d9f8765..1a314e414 100644
--- a/tests/modules/services/gpg-agent/override-homedir.nix
+++ b/tests/modules/services/gpg-agent/override-homedir.nix
@@ -12,6 +12,7 @@ with lib;
     };
 
     test.stubs.gnupg = { };
+    test.stubs.systemd = { }; # depends on gnupg.override
 
     nmt.script = ''
       in="${config.systemd.user.sockets.gpg-agent.Socket.ListenStream}"