diff --git a/pkgs/build-support/fetchgit/tests.nix b/pkgs/build-support/fetchgit/tests.nix
new file mode 100644
index 000000000000..6805473e2968
--- /dev/null
+++ b/pkgs/build-support/fetchgit/tests.nix
@@ -0,0 +1,10 @@
+{ invalidateFetcherByDrvHash, fetchgit, ... }:
+
+{
+  simple = invalidateFetcherByDrvHash fetchgit {
+    name = "nix-source";
+    url = "https://github.com/NixOS/nix";
+    rev = "9d9dbe6ed05854e03811c361a3380e09183f4f4a";
+    sha256 = "sha256-7DszvbCNTjpzGRmpIVAWXk20P0/XTrWZ79KSOGLrUWY=";
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 6b70b14f9ebb..deee409c6faf 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -441,10 +441,12 @@ with pkgs;
 
   fetchfossil = callPackage ../build-support/fetchfossil { };
 
-  fetchgit = callPackage ../build-support/fetchgit {
+  fetchgit = (callPackage ../build-support/fetchgit {
     git = buildPackages.gitMinimal;
     cacert = buildPackages.cacert;
     git-lfs = buildPackages.git-lfs;
+  }) // { # fetchgit is a function, so we use // instead of passthru.
+    tests = callPackages ../build-support/fetchgit/tests.nix {};
   };
 
   fetchgitLocal = callPackage ../build-support/fetchgitlocal { };