diff --git a/pkgs/by-name/ni/nim-unwrapped/package.nix b/pkgs/by-name/ni/nim-unwrapped/package.nix
index 08389b6d9a7c..d22fa8a7e090 100644
--- a/pkgs/by-name/ni/nim-unwrapped/package.nix
+++ b/pkgs/by-name/ni/nim-unwrapped/package.nix
@@ -49,6 +49,11 @@ stdenv.mkDerivation (finalAttrs: {
         pname = "nim-bootstrap";
         inherit (finalAttrs) version src preBuild;
         enableParallelBuilding = true;
+        buildPhase = ''
+          runHook preBuild
+          ./build.sh
+          runHook postBuild
+        '';
         installPhase = ''
           runHook preInstall
           install -Dt $out/bin bin/nim