diff --git a/src/st/meson.build b/src/st/meson.build
index 1ae9653b3..061c5adf2 100644
--- a/src/st/meson.build
+++ b/src/st/meson.build
@@ -204,7 +204,8 @@ if get_option('tests')
   )
 
   test('CSS styling support', test_theme,
-    workdir: meson.current_source_dir()
+    workdir: meson.current_source_dir(),
+    env: ['GSETTINGS_BACKEND=memory']
   )
 endif