diff --git a/tests/modules/programs/mbsync/mbsync-master-slave-change.nix b/tests/modules/programs/mbsync/mbsync-master-slave-change.nix
index 96f02d90..2e877320 100644
--- a/tests/modules/programs/mbsync/mbsync-master-slave-change.nix
+++ b/tests/modules/programs/mbsync/mbsync-master-slave-change.nix
@@ -85,6 +85,8 @@ with lib;
       "mbsync channels no longer use slavePattern. Use nearPattern in its place."
     ];
 
+    test.stubs.isync = { };
+
     nmt.script = ''
       assertFileExists home-files/.mbsyncrc
       assertFileContent home-files/.mbsyncrc ${./mbsync-expected.conf}
diff --git a/tests/modules/programs/mbsync/mbsync.nix b/tests/modules/programs/mbsync/mbsync.nix
index d80421d6..7042760a 100644
--- a/tests/modules/programs/mbsync/mbsync.nix
+++ b/tests/modules/programs/mbsync/mbsync.nix
@@ -75,6 +75,8 @@ with lib;
       };
     };
 
+    test.stubs.isync = { };
+
     nmt.script = ''
       assertFileExists home-files/.mbsyncrc
       assertFileContent home-files/.mbsyncrc ${./mbsync-expected.conf}