diff --git a/nixos/modules/services/x11/display-managers/gdm.nix b/nixos/modules/services/x11/display-managers/gdm.nix
index 6cc30b218f4a..226fee7491c1 100644
--- a/nixos/modules/services/x11/display-managers/gdm.nix
+++ b/nixos/modules/services/x11/display-managers/gdm.nix
@@ -116,7 +116,7 @@ in
         environment = {
           GDM_X_SERVER_EXTRA_ARGS = toString
             (filter (arg: arg != "-terminate") cfg.xserverArgs);
-          GDM_SESSIONS_DIR = "${cfg.session.desktops}/share/xsessions";
+          XDG_DATA_DIRS = "${cfg.session.desktops}/share/";
           # Find the mouse
           XCURSOR_PATH = "~/.icons:${pkgs.gnome3.adwaita-icon-theme}/share/icons";
         } // optionalAttrs (xSessionWrapper != null) {
diff --git a/pkgs/desktops/gnome-3/core/gdm/default.nix b/pkgs/desktops/gnome-3/core/gdm/default.nix
index c419df5093e9..691049cf655d 100644
--- a/pkgs/desktops/gnome-3/core/gdm/default.nix
+++ b/pkgs/desktops/gnome-3/core/gdm/default.nix
@@ -46,10 +46,6 @@ stdenv.mkDerivation rec {
     # The following patches implement certain environment variables in GDM which are set by
     # the gdm configuration module (nixos/modules/services/x11/display-managers/gdm.nix).
 
-    # Look for session definition files in the directory specified by GDM_SESSIONS_DIR.
-    ./sessions_dir.patch
-
-    # Allow specifying X server arguments with GDM_X_SERVER_EXTRA_ARGS.
     ./gdm-x-session_extra_args.patch
 
     # Allow specifying a wrapper for running the session command.
diff --git a/pkgs/desktops/gnome-3/core/gdm/sessions_dir.patch b/pkgs/desktops/gnome-3/core/gdm/sessions_dir.patch
deleted file mode 100644
index cda0468d3493..000000000000
--- a/pkgs/desktops/gnome-3/core/gdm/sessions_dir.patch
+++ /dev/null
@@ -1,38 +0,0 @@
---- a/daemon/gdm-launch-environment.c
-+++ b/daemon/gdm-launch-environment.c
-@@ -143,6 +143,7 @@
-                 "WINDOWPATH",
-                 "XCURSOR_PATH",
-                 "XDG_CONFIG_DIRS",
-+                "GDM_SESSIONS_DIR",
-                 NULL
-         };
-         char *system_data_dirs;
---- a/daemon/gdm-session.c
-+++ b/daemon/gdm-session.c
-@@ -364,6 +364,11 @@
-                 g_array_append_val (search_array, dir);
-         }
- 
-+        if (getenv("GDM_SESSIONS_DIR") != NULL) {
-+                gchar *gdm_sessions_dir = g_getenv("GDM_SESSIONS_DIR");
-+                g_array_append_val (search_array, gdm_sessions_dir);
-+        };
-+
-         g_array_append_vals (search_array, x_search_dirs, G_N_ELEMENTS (x_search_dirs));
- 
- #ifdef ENABLE_WAYLAND_SUPPORT
---- a/libgdm/gdm-sessions.c
-+++ b/libgdm/gdm-sessions.c
-@@ -236,6 +236,11 @@
-                 g_array_append_val (xorg_search_array, session_dir);
-         }
- 
-+        if (g_getenv("GDM_SESSIONS_DIR") != NULL) {
-+                gchar *gdm_sessions_dir = g_getenv("GDM_SESSIONS_DIR");
-+                g_array_append_val (xorg_search_array, gdm_sessions_dir);
-+        };
-+
-         g_array_append_vals (xorg_search_array, xorg_search_dirs, G_N_ELEMENTS (xorg_search_dirs));
- 
- #ifdef ENABLE_WAYLAND_SUPPORT