diff --git a/pkgs/development/libraries/libgtop/default.nix b/pkgs/development/libraries/libgtop/default.nix
index 98b0dc89fee..51765508098 100644
--- a/pkgs/development/libraries/libgtop/default.nix
+++ b/pkgs/development/libraries/libgtop/default.nix
@@ -13,6 +13,8 @@ stdenv.mkDerivation rec {
   pname = "libgtop";
   version = "2.40.0";
 
+  outputs = [ "out" "dev" ];
+
   src = fetchurl {
     url = "mirror://gnome/sources/${pname}/${lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
     sha256 = "1m6jbqk8maa52gxrf223442fr5bvvxgb7ham6v039i3r1i62gwvq";