diff --git a/pkgs/development/libraries/gtkmm/2.x.nix b/pkgs/development/libraries/gtkmm/2.x.nix
index 119e3f77f670..1ec2a7cd6f0d 100644
--- a/pkgs/development/libraries/gtkmm/2.x.nix
+++ b/pkgs/development/libraries/gtkmm/2.x.nix
@@ -9,6 +9,8 @@ stdenv.mkDerivation rec {
     sha256 = "0680a53b7bf90b4e4bf444d1d89e6df41c777e0bacc96e9c09fc4dd2f5fe6b72";
   };
 
+  outputs = [ "out" "dev" ];
+
   nativeBuildInputs = [pkgconfig];
 
   propagatedBuildInputs = [ glibmm gtk2 atkmm cairomm pangomm ];