diff --git a/src/gtk/frame.cpp b/src/gtk/frame.cpp
index 3705e6ab60..0f54dc32b9 100644
--- a/src/gtk/frame.cpp
+++ b/src/gtk/frame.cpp
@@ -1117,9 +1117,14 @@ void wxFrame::Iconize( bool iconize )
 {
    if (iconize)
    {
-        XIconifyWindow( GDK_WINDOW_XDISPLAY( m_widget->window ),
-                        GDK_WINDOW_XWINDOW( m_widget->window ),
-                        DefaultScreen( GDK_DISPLAY() ) );
+       GdkWindow *window = m_widget->window;
+
+       // you should do it later, for example from OnCreate() handler
+       wxCHECK_RET( window, _T("frame not created yet - can't iconize") );
+
+       XIconifyWindow(GDK_WINDOW_XDISPLAY(window),
+                      GDK_WINDOW_XWINDOW(window),
+                      DefaultScreen(GDK_DISPLAY()));
    }
 }
 
diff --git a/src/gtk1/frame.cpp b/src/gtk1/frame.cpp
index 3705e6ab60..0f54dc32b9 100644
--- a/src/gtk1/frame.cpp
+++ b/src/gtk1/frame.cpp
@@ -1117,9 +1117,14 @@ void wxFrame::Iconize( bool iconize )
 {
    if (iconize)
    {
-        XIconifyWindow( GDK_WINDOW_XDISPLAY( m_widget->window ),
-                        GDK_WINDOW_XWINDOW( m_widget->window ),
-                        DefaultScreen( GDK_DISPLAY() ) );
+       GdkWindow *window = m_widget->window;
+
+       // you should do it later, for example from OnCreate() handler
+       wxCHECK_RET( window, _T("frame not created yet - can't iconize") );
+
+       XIconifyWindow(GDK_WINDOW_XDISPLAY(window),
+                      GDK_WINDOW_XWINDOW(window),
+                      DefaultScreen(GDK_DISPLAY()));
    }
 }