diff --git a/pkgs/by-name/un/unarc/package.nix b/pkgs/by-name/un/unarc/package.nix
new file mode 100644
index 000000000000..5b1829ab5cae
--- /dev/null
+++ b/pkgs/by-name/un/unarc/package.nix
@@ -0,0 +1,43 @@
+{
+  stdenv,
+  unstableGitUpdater,
+  fetchFromGitHub,
+  lib,
+}:
+
+stdenv.mkDerivation {
+  pname = "unarc";
+  version = "0-unstable-2020-06-05";
+
+  src = fetchFromGitHub {
+    owner = "xredor";
+    repo = "unarc";
+    rev = "adc333d6cdd76d72da254cc80d766fbbcc683c95";
+    hash = "sha256-ysOei44P3K+aA+h73DuHlgwTKqQx/Xq8z+DefB6Qhcs=";
+  };
+
+  postPatch = ''
+    substituteInPlace 'CUI.h' \
+      --replace-fail 'fgets(answer, 256, stdin);' 'if (!fgets (answer, 256, stdin)) return FALSE;' \
+      --replace-fail 'printf (help)' 'printf ("%s", help)'
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/bin
+    install -m755 unarc $out/bin
+
+    runHook postInstall
+  '';
+
+  passthru.updateScript = unstableGitUpdater { };
+
+  meta = {
+    description = "Unpacker for ArC (FreeArc) archives ('ArC\\1' header)";
+    homepage = "https://github.com/xredor/unarc";
+    license = lib.licenses.unfree; # unknown
+    maintainers = [ lib.maintainers.lucasew ];
+    mainProgram = "unarc";
+  };
+}