diff --git a/nixos/modules/services/x11/desktop-managers/enlightenment.nix b/nixos/modules/services/x11/desktop-managers/enlightenment.nix
index da3287aaea6ec..ee819cb88d7b1 100644
--- a/nixos/modules/services/x11/desktop-managers/enlightenment.nix
+++ b/nixos/modules/services/x11/desktop-managers/enlightenment.nix
@@ -33,7 +33,12 @@ in
       pkgs.xorg.xauth # used by kdesu
       pkgs.gtk2 # To get GTK+'s themes.
       pkgs.tango-icon-theme
+
+      # having these utilities on the path makes the system 
+      # path builder update mime entries
       pkgs.shared-mime-info
+      pkgs.desktop-file-utils
+
       pkgs.gnome2.gnomeicontheme
       pkgs.xorg.xcursorthemes
     ];
diff --git a/nixos/modules/services/x11/desktop-managers/plasma5.nix b/nixos/modules/services/x11/desktop-managers/plasma5.nix
index 17733aa7e4f64..129c876abb51f 100644
--- a/nixos/modules/services/x11/desktop-managers/plasma5.nix
+++ b/nixos/modules/services/x11/desktop-managers/plasma5.nix
@@ -162,6 +162,11 @@ in
 
           libsForQt56.phonon-backend-gstreamer
           libsForQt5.phonon-backend-gstreamer
+
+          # having these utilities on the path makes the system 
+          # path builder update mime entries
+          shared-mime-info
+          desktop-file-utils
         ]
 
         ++ lib.optionals cfg.enableQt4Support [ pkgs.phonon-backend-gstreamer ]
diff --git a/nixos/modules/services/x11/desktop-managers/xfce.nix b/nixos/modules/services/x11/desktop-managers/xfce.nix
index ae155470419d5..a016085af02d8 100644
--- a/nixos/modules/services/x11/desktop-managers/xfce.nix
+++ b/nixos/modules/services/x11/desktop-managers/xfce.nix
@@ -59,6 +59,8 @@ in
       tango-icon-theme
       xfce4-icon-theme
 
+      # having these utilities on the path makes the system 
+      # path builder update mime entries
       desktop-file-utils
       shared-mime-info
 
diff --git a/pkgs/desktops/gnome-3/default.nix b/pkgs/desktops/gnome-3/default.nix
index 15707575e7f3d..4ca544194e91d 100644
--- a/pkgs/desktops/gnome-3/default.nix
+++ b/pkgs/desktops/gnome-3/default.nix
@@ -11,8 +11,11 @@ lib.makeScope pkgs.newScope (self: with self; {
   maintainers = with pkgs.lib.maintainers; [ lethalman jtojnar ];
 
   corePackages = with gnome3; [
+    # having these utilities on the path makes the system 
+    # path builder update mime entries
     pkgs.desktop-file-utils
-    pkgs.shared-mime-info # for update-mime-database
+    pkgs.shared-mime-info 
+
     glib # for gsettings
     gtk3.out # for gtk-update-icon-cache
     glib-networking gvfs dconf gnome-backgrounds gnome-control-center