diff --git a/src/tests/input-capture-tests.c b/src/tests/input-capture-tests.c
index 0a066f7d8..0a5b40d68 100644
--- a/src/tests/input-capture-tests.c
+++ b/src/tests/input-capture-tests.c
@@ -597,8 +597,6 @@ main (int    argc,
   g_autoptr (MetaContext) context = NULL;
   g_autoptr (GError) error = NULL;
 
-  g_assert_cmpstr (getenv ("GSETTINGS_BACKEND"), ==, "memory");
-
   context = test_context =
     meta_create_test_context (META_CONTEXT_TEST_TYPE_HEADLESS,
                               META_CONTEXT_TEST_FLAG_NO_X11);
diff --git a/src/tests/meta-context-test.c b/src/tests/meta-context-test.c
index 51407f5e1..558d9f35a 100644
--- a/src/tests/meta-context-test.c
+++ b/src/tests/meta-context-test.c
@@ -66,6 +66,9 @@ ensure_gsettings_memory_backend (void)
   g_autoptr (GSettingsBackend) memory_backend = NULL;
   GSettingsBackend *default_backend;
 
+  g_assert_cmpstr (getenv ("GSETTINGS_BACKEND"), ==, "memory");
+  g_assert_cmpstr (getenv ("XDG_CURRENT_DESKTOP"), ==, "");
+
   memory_backend = g_memory_settings_backend_new ();
   default_backend = g_settings_backend_get_default ();
   g_assert_true (G_TYPE_FROM_INSTANCE (memory_backend) ==
diff --git a/src/tests/mutter_dbusrunner.py b/src/tests/mutter_dbusrunner.py
index 45407ba0f..9bda2848b 100644
--- a/src/tests/mutter_dbusrunner.py
+++ b/src/tests/mutter_dbusrunner.py
@@ -265,6 +265,7 @@ def wrap_call(args, wrapper):
     env['NO_AT_BRIDGE'] = '1'
     env['GTK_A11Y'] = 'none'
     env['GSETTINGS_BACKEND'] = 'memory'
+    env['XDG_CURRENT_DESKTOP'] = ''
     env['META_DBUS_RUNNER_ACTIVE'] = '1'
 
     if wrapper == 'gdb':
diff --git a/src/tests/stacking.test.in b/src/tests/stacking.test.in
index c26ec7478..63438da6d 100644
--- a/src/tests/stacking.test.in
+++ b/src/tests/stacking.test.in
@@ -4,6 +4,6 @@ Description=Mutter stacking test: @stacking_test@
 # a solution for
 # https://gitlab.gnome.org/GNOME/gnome-desktop-testing/-/issues/1,
 # and anyway that wouldn't be sufficient to handle XDG_RUNTIME_DIR
-Exec=sh -ec 'env GSETTINGS_BACKEND=memory XDG_RUNTIME_DIR="$(mktemp -d -t mutter-@apiversion@-@stacking_test@-XXXXXX)" @libexecdir@/installed-tests/mutter-@apiversion@/mutter-installed-dbus-session.py xvfb-run -a -s "+iglx -noreset" -- @libexecdir@/installed-tests/mutter-@apiversion@/mutter-test-runner @tests_datadir@/stacking/@stacking_test@.metatest'
+Exec=sh -ec 'env GSETTINGS_BACKEND=memory XDG_CURRENT_DESKTOP= XDG_RUNTIME_DIR="$(mktemp -d -t mutter-@apiversion@-@stacking_test@-XXXXXX)" @libexecdir@/installed-tests/mutter-@apiversion@/mutter-installed-dbus-session.py xvfb-run -a -s "+iglx -noreset" -- @libexecdir@/installed-tests/mutter-@apiversion@/mutter-test-runner @tests_datadir@/stacking/@stacking_test@.metatest'
 Type=session
 Output=TAP