diff --git a/pkgs/by-name/si/signal-desktop/package.nix b/pkgs/by-name/si/signal-desktop/package.nix
index 4a2b38b0be51..bb9fa6b38835 100644
--- a/pkgs/by-name/si/signal-desktop/package.nix
+++ b/pkgs/by-name/si/signal-desktop/package.nix
@@ -1,4 +1,5 @@
 {
+  actool,
   stdenv,
   lib,
   nodejs_24,
@@ -93,6 +94,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   strictDeps = true;
   nativeBuildInputs = [
+    actool
     node-gyp
     nodejs
     pnpmConfigHook