diff --git a/docs/changes.txt b/docs/changes.txt
index 771ea9f542..edae6b67be 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -234,6 +234,8 @@ wxGTK:
   in wxSystemSettings::GetMetric (Mart Raudsepp)
 - wxGTK uses GTK+ 2.x by default now, you have to pass --disable-gtk2 to
   configure if you want to use GTK+ 1.2
+- implemented wxTopLevel::IsMaximized() for GTK+2 and WMs that implement
+  freedesktop.org's wm-spec (Mart Raudsepp)
 
 wxMotif:
 
diff --git a/src/gtk/toplevel.cpp b/src/gtk/toplevel.cpp
index 507e47463a..d2a5bdd6b1 100644
--- a/src/gtk/toplevel.cpp
+++ b/src/gtk/toplevel.cpp
@@ -936,10 +936,17 @@ void wxTopLevelWindowGTK::Maximize(bool maximize)
 
 bool wxTopLevelWindowGTK::IsMaximized() const
 {
+#ifdef __WXGTK20__
+    if(!m_widget->window)
+        return false;
+
+    return gdk_window_get_state(m_widget->window) & GDK_WINDOW_STATE_MAXIMIZED;
+#else
   //    wxFAIL_MSG( _T("not implemented") );
 
     // This is an approximation
     return FALSE;
+#endif
 }
 
 void wxTopLevelWindowGTK::Restore()
diff --git a/src/gtk1/toplevel.cpp b/src/gtk1/toplevel.cpp
index 507e47463a..d2a5bdd6b1 100644
--- a/src/gtk1/toplevel.cpp
+++ b/src/gtk1/toplevel.cpp
@@ -936,10 +936,17 @@ void wxTopLevelWindowGTK::Maximize(bool maximize)
 
 bool wxTopLevelWindowGTK::IsMaximized() const
 {
+#ifdef __WXGTK20__
+    if(!m_widget->window)
+        return false;
+
+    return gdk_window_get_state(m_widget->window) & GDK_WINDOW_STATE_MAXIMIZED;
+#else
   //    wxFAIL_MSG( _T("not implemented") );
 
     // This is an approximation
     return FALSE;
+#endif
 }
 
 void wxTopLevelWindowGTK::Restore()