diff --git a/flatpak/net.zoite.Zoitechat.json b/flatpak/net.zoite.Zoitechat.json
index 48c0f7ab..f127fe3f 100644
--- a/flatpak/net.zoite.Zoitechat.json
+++ b/flatpak/net.zoite.Zoitechat.json
@@ -16,6 +16,7 @@
     "--filesystem=~/.themes:ro",
     "--filesystem=~/.icons:ro",
     "--filesystem=xdg-run/tray-icon:create",
+    "--env=GTK_CSD=1",
 
     "--talk-name=org.freedesktop.Notifications",
     "--talk-name=org.kde.StatusNotifierWatcher",