diff --git a/Makefile b/Makefile
index 35152e4..0707839 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 prefix ?= /usr/local
 bindir = $(prefix)/bin
 libdir = $(prefix)/lib
-libexecdir = $(prefix)/libexec
+libexecdir ?= $(prefix)/libexec
 includedir = $(prefix)/include
 datarootdir = $(prefix)/share
 datadir = $(datarootdir)
@@ -34,7 +34,7 @@ $(BIN): Cargo.toml Cargo.lock src/main.rs vendor-check
 
 install:
 	install -Dm0755 target/$(TARGET)/$(BIN) $(DESTDIR)$(libexecdir)/$(BIN)
-	install -Dm0644 data/$(DBUS_NAME).service $(DESTDIR)/$(datadir)/dbus-1/services/$(DBUS_NAME).service
+	install -Dm0644 data/$(DBUS_NAME).service $(DESTDIR)/$(datadir)/systemd/user/$(DBUS_NAME).service
 	install -Dm0644 data/cosmic.portal $(DESTDIR)/$(datadir)/xdg-desktop-portal/portals/cosmic.portal
 
 ## Cargo Vendoring
diff --git a/flake.nix b/flake.nix
index 33a6f90..8ba3a2d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -28,9 +28,11 @@
               ./src
               ./Cargo.toml
               ./Cargo.lock
+              ./Makefile
+              ./data
             ];
           };
-          nativeBuildInputs = with pkgs; [ pkg-config rustPlatform.bindgenHook ];
+          nativeBuildInputs = with pkgs; [ pkg-config rustPlatform.bindgenHook gnumake ];
           buildInputs = with pkgs; [
             pipewire
             libxkbcommon
@@ -47,7 +49,15 @@
           inherit xdg-desktop-portal-cosmic;
         };
 
-        packages.default = xdg-desktop-portal-cosmic;
+        # FIXME reference the libexecdir for xdp-cosmic in the nix store in cosmic-session
+        # then the hack putting xdp-cosmic into bin can be removed
+        packages.default = xdg-desktop-portal-cosmic
+        .overrideAttrs (oldAttrs: rec {
+          installPhase = ''
+            make install prefix=$out libexecdir=$out/bin
+          '';
+          passthru.providedSessions = [ "cosmic" ];
+        });
 
         apps.default = flake-utils.lib.mkApp {
           drv = xdg-desktop-portal-cosmic;