diff --git a/pkgs/by-name/pi/pinact/package.nix b/pkgs/by-name/pi/pinact/package.nix
index 399c9caee856..81849bb79419 100644
--- a/pkgs/by-name/pi/pinact/package.nix
+++ b/pkgs/by-name/pi/pinact/package.nix
@@ -1,24 +1,26 @@
 {
   lib,
+  stdenv,
   fetchFromGitHub,
   buildGoModule,
+  installShellFiles,
   versionCheckHook,
   nix-update-script,
 }:
 
 let
+  mainProgram = "pinact";
+in
+buildGoModule (finalAttrs: {
   pname = "pinact";
   version = "3.1.2";
+
   src = fetchFromGitHub {
     owner = "suzuki-shunsuke";
     repo = "pinact";
-    tag = "v${version}";
+    tag = "v${finalAttrs.version}";
     hash = "sha256-5jJzlMMpfk9fFDoqR0NJNacquZ4Zma0YF/pi80Miv0Y=";
   };
-  mainProgram = "pinact";
-in
-buildGoModule {
-  inherit pname version src;
 
   vendorHash = "sha256-kK4r0mCktlbhJr6iHD0Q/k1DralieN2AUg+zREZ06DA=";
 
@@ -26,6 +28,17 @@ buildGoModule {
 
   doCheck = true;
 
+  nativeBuildInputs = [
+    installShellFiles
+  ];
+
+  postInstall = lib.optionalString (stdenv.buildPlatform.canExecute stdenv.hostPlatform) ''
+    installShellCompletion --cmd '${mainProgram}' \
+      --bash <("$out/bin/${mainProgram}" completion bash) \
+      --zsh <("$out/bin/${mainProgram}" completion zsh) \
+      --fish <("$out/bin/${mainProgram}" completion fish)
+  '';
+
   nativeInstallCheckInputs = [
     versionCheckHook
   ];
@@ -40,7 +53,7 @@ buildGoModule {
   ldflags = [
     "-s"
     "-w"
-    "-X main.version=${version} -X main.commit=v${version}"
+    "-X main.version=${finalAttrs.version} -X main.commit=v${finalAttrs.version}"
   ];
 
   subPackages = [
@@ -51,8 +64,8 @@ buildGoModule {
     inherit mainProgram;
     description = "Pin GitHub Actions versions";
     homepage = "https://github.com/suzuki-shunsuke/pinact";
-    changelog = "https://github.com/suzuki-shunsuke/pinact/releases/tag/v${version}";
+    changelog = "https://github.com/suzuki-shunsuke/pinact/releases/tag/v${finalAttrs.version}";
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ kachick ];
   };
-}
+})