diff --git a/src/gtk/window.cpp b/src/gtk/window.cpp
index fd76da760f..9bd0dc994e 100644
--- a/src/gtk/window.cpp
+++ b/src/gtk/window.cpp
@@ -4370,7 +4370,8 @@ void wxWindowGTK::DoApplyWidgetStyle(GtkRcStyle *style)
 {
     if (m_wxwindow)
         gtk_widget_modify_style(m_wxwindow, style);
-    gtk_widget_modify_style(m_widget, style);
+    else
+        gtk_widget_modify_style(m_widget, style);
 }
 
 bool wxWindowGTK::SetBackgroundStyle(wxBackgroundStyle style)
diff --git a/src/gtk1/window.cpp b/src/gtk1/window.cpp
index fd76da760f..9bd0dc994e 100644
--- a/src/gtk1/window.cpp
+++ b/src/gtk1/window.cpp
@@ -4370,7 +4370,8 @@ void wxWindowGTK::DoApplyWidgetStyle(GtkRcStyle *style)
 {
     if (m_wxwindow)
         gtk_widget_modify_style(m_wxwindow, style);
-    gtk_widget_modify_style(m_widget, style);
+    else
+        gtk_widget_modify_style(m_widget, style);
 }
 
 bool wxWindowGTK::SetBackgroundStyle(wxBackgroundStyle style)