diff --git a/src/qt/toplevel.cpp b/src/qt/toplevel.cpp
index 79969cc52d..35a982f5ff 100644
--- a/src/qt/toplevel.cpp
+++ b/src/qt/toplevel.cpp
@@ -120,7 +120,15 @@ void wxTopLevelWindowQt::SetIcons( const wxIconBundle& icons )
 void wxTopLevelWindowQt::SetWindowStyleFlag( long style )
 {
     wxWindow::SetWindowStyleFlag( style );
-    
+
+    if ( HasFlag( wxCENTRE ) )
+    {
+        Centre();
+    }
+
+    if(!GetHandle())
+        return;
+
     Qt::WindowFlags qtFlags = GetHandle()->windowFlags();
     
     if ( HasFlag( wxSTAY_ON_TOP ) != qtFlags.testFlag( Qt::WindowStaysOnTopHint ) )
@@ -167,12 +175,7 @@ void wxTopLevelWindowQt::SetWindowStyleFlag( long style )
         GetHandle()->setSizePolicy( QSizePolicy::Preferred, QSizePolicy::Preferred );
     else
         GetHandle()->setSizePolicy( QSizePolicy::Fixed, QSizePolicy::Fixed );
-    
-    if ( HasFlag( wxCENTRE ) )
-    {
-        Centre();
     }
-}
 
 long wxTopLevelWindowQt::GetWindowStyleFlag() const
 {
diff --git a/src/qt/window.cpp b/src/qt/window.cpp
index d651bba261..4d034a08d6 100644
--- a/src/qt/window.cpp
+++ b/src/qt/window.cpp
@@ -741,6 +741,9 @@ void wxWindowQt::SetWindowStyleFlag( long style )
 //        qtFrame->setFrameShadow( QFrame::Plain );
 //    }
 
+    if(!GetHandle())
+        return;
+
     Qt::WindowFlags qtFlags = GetHandle()->windowFlags();
 
     if ( HasFlag( wxFRAME_NO_TASKBAR ) )