diff --git a/pkgs/by-name/pr/prmt/package.nix b/pkgs/by-name/pr/prmt/package.nix
index 390cb945f73f..ed694fd6be6d 100644
--- a/pkgs/by-name/pr/prmt/package.nix
+++ b/pkgs/by-name/pr/prmt/package.nix
@@ -19,7 +19,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
   cargoHash = "sha256-Vc2uCFD3A3huSFaYbgZHRWgiQnxXkz7BzvmdT7AsnoY=";
 
   # Fail to run in sandbox environment
-  checkFlags = map (t: "--skip ${t}") [
+  checkFlags = map (t: "--skip=${t}") [
     "modules::path::tests::relative_path_inside_home_renders_tilde"
     "modules::path::tests::relative_path_with_shared_prefix_is_not_tilde"
     "test_git_module"