diff --git a/home/gui/default.nix b/home/gui/default.nix
index b3056bb..2cc8ffb 100644
--- a/home/gui/default.nix
+++ b/home/gui/default.nix
@@ -11,6 +11,7 @@
 	home.packages = with pkgs; [
 		bazel
 		bazel-buildtools
+		bitwarden
 		cdrtools
 		ffmpeg
 		gopls
@@ -24,7 +25,6 @@
 			libreoffice-bin
 		] else
 		[
-			bitwarden
 			gnucash
 			handbrake
 			jellyfin-media-player
diff --git a/overlays/default.nix b/overlays/default.nix
index 79d8990..2d10d17 100644
--- a/overlays/default.nix
+++ b/overlays/default.nix
@@ -60,4 +60,5 @@ in rec {
 		propagatedBuildInputs = old.propagatedBuildInputs ++ [ my-py-addons.xonsh-direnv ];
 	});
 
+	bitwarden = if super.stdenv.isDarwin then (super.callPackage ./mac/bitwarden.nix {}) else super.bitwarden;
 }
diff --git a/overlays/hms.sh b/overlays/hms.sh
index af3f656..0060746 100644
--- a/overlays/hms.sh
+++ b/overlays/hms.sh
@@ -27,8 +27,14 @@ popd > /dev/null
 rm -r "${dest}"
 
 if [ "$(uname -s)" == "Darwin" ]; then
-	for app in ~/.nix-profile/Applications/*.app; do
-		echo "Copying '${app}' to Applications"
-		cp -r "${app}" "${HOME}/Applications"
+	cd ~/.nix-profile/Applications
+	for app in *.app; do
+		echo "Updating permissions on '${app}'"
+		chmod -R u+w "${HOME}/Applications/${app}"
+		echo "Copying new version to Applications"
+		cp -r "${app}" "${HOME}/Applications" 2>&1 > /dev/null || true
+		if [ "$?" != "0" ]; then
+			echo "An error occurred, proceeding anyway"
+		fi
 	done
 fi
diff --git a/overlays/mac/bitwarden.nix b/overlays/mac/bitwarden.nix
new file mode 100644
index 0000000..6c9277c
--- /dev/null
+++ b/overlays/mac/bitwarden.nix
@@ -0,0 +1,32 @@
+{ stdenv, fetchurl,
+  undmg,
+}:
+
+stdenv.mkDerivation rec {
+	version = "2022.10.1";
+	pname = "Bitwarden";
+
+	buildInputs = [
+		undmg
+	];
+	sourceRoot = ".";
+	phases = [
+		"unpackPhase"
+		"installPhase"
+	];
+	installPhase = ''
+		mkdir -p "$out/Applications"
+		cp -r Bitwarden*.app "$out/Applications"
+	'';
+
+	src = fetchurl {
+		name = "Bitwarden-${version}.dmg";
+		url = "https://github.com/bitwarden/clients/releases/download/desktop-v${version}/Bitwarden-${version}-universal.dmg";
+		sha256 = "sha256-6O8xaGBaG4d6l9QRtGM5wj9OCMFy87dH8N1MfEBBjck=";
+	};
+
+	meta = {
+		description = "Bitwarden, an open source password management tool";
+		homepage = "https://bitwarden.com";
+	};
+}