diff --git a/src/client/qwaylandintegration.cpp b/src/client/qwaylandintegration.cpp
index 13bacc9b..7c35003d 100644
--- a/src/client/qwaylandintegration.cpp
+++ b/src/client/qwaylandintegration.cpp
@@ -88,6 +88,9 @@ QWaylandIntegration::QWaylandIntegration()
 
     QWaylandWindow::fixedToplevelPositions =
             !qEnvironmentVariableIsSet("QT_WAYLAND_DISABLE_FIXED_POSITIONS");
+
+    if (!qEnvironmentVariableIsSet("QT_WAYLAND_DECORATION"))
+        qputenv("QT_WAYLAND_DECORATION", "adwaita");
 }
 
 QWaylandIntegration::~QWaylandIntegration()