diff --git a/pkgs/build-support/fetchfirefoxaddon/tests.nix b/pkgs/build-support/fetchfirefoxaddon/tests.nix
new file mode 100644
index 000000000000..d125be196aff
--- /dev/null
+++ b/pkgs/build-support/fetchfirefoxaddon/tests.nix
@@ -0,0 +1,10 @@
+{ invalidateFetcherByDrvHash, fetchFirefoxAddon, ... }:
+
+{
+  simple = invalidateFetcherByDrvHash fetchFirefoxAddon {
+    name = "image-search-options";
+    # Chosen because its only 147KB
+    url = "https://addons.mozilla.org/firefox/downloads/file/3059971/image_search_options-3.0.12-fx.xpi";
+    sha256 = "sha256-H73YWX/DKxvhEwKpWOo7orAQ7c/rQywpljeyxYxv0Gg=";
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 36c9ab1fe70f..94b47b96620e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -506,7 +506,10 @@ with pkgs;
 
   fetchhg = callPackage ../build-support/fetchhg { };
 
-  fetchFirefoxAddon = callPackage ../build-support/fetchfirefoxaddon {};
+  fetchFirefoxAddon = callPackage ../build-support/fetchfirefoxaddon { }
+    // {
+      tests = callPackages ../build-support/fetchfirefoxaddon/tests.nix { };
+    };
 
   # `fetchurl' downloads a file from the network.
   fetchurl = if stdenv.buildPlatform != stdenv.hostPlatform