diff --git a/include/wx/settings.h b/include/wx/settings.h
index f66acfe179..eb32ec5336 100644
--- a/include/wx/settings.h
+++ b/include/wx/settings.h
@@ -216,7 +216,7 @@ public:
     static wxFont GetFont(wxSystemFont index);
 
     // get a system-dependent metric
-    static int GetMetric(wxSystemMetric index, wxWindow * win = NULL);
+    static int GetMetric(wxSystemMetric index, const wxWindow* win = NULL);
 
     // get the object describing the current system appearance
     static wxSystemAppearance GetAppearance();
@@ -240,7 +240,7 @@ public:
 
     // some metrics are toolkit-dependent and provided by wxUniv, some are
     // lowlevel
-    static int GetMetric(wxSystemMetric index, wxWindow *win = NULL);
+    static int GetMetric(wxSystemMetric index, const wxWindow* win = NULL);
 #endif // __WXUNIVERSAL__
 
     // Get system screen design (desktop, pda, ..) used for
diff --git a/src/common/wincmn.cpp b/src/common/wincmn.cpp
index 1073c4ea4e..4939c3be30 100644
--- a/src/common/wincmn.cpp
+++ b/src/common/wincmn.cpp
@@ -804,7 +804,7 @@ double wxWindowBase::GetContentScaleFactor() const
 static int wxGetMetricOrDefault(wxSystemMetric what, const wxWindowBase* win)
 {
     int rc = wxSystemSettings::GetMetric(
-        what, static_cast<wxWindow*>(const_cast<wxWindowBase*>(win)));
+        what, static_cast<const wxWindow*>(win));
     if ( rc == -1 )
     {
         switch ( what )
diff --git a/src/dfb/settings.cpp b/src/dfb/settings.cpp
index b97895baf5..f6137bde60 100644
--- a/src/dfb/settings.cpp
+++ b/src/dfb/settings.cpp
@@ -63,7 +63,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 }
 
 int wxSystemSettingsNative::GetMetric(wxSystemMetric index,
-                                      wxWindow* WXUNUSED(win))
+                                      const wxWindow* WXUNUSED(win))
 {
     int val;
 
diff --git a/src/generic/scrlwing.cpp b/src/generic/scrlwing.cpp
index db02c0290d..291e2f16af 100644
--- a/src/generic/scrlwing.cpp
+++ b/src/generic/scrlwing.cpp
@@ -1553,12 +1553,11 @@ wxSize wxScrolledT_Helper::FilterBestSize(const wxWindow *win,
 
         wxSize minSize = win->GetMinSize();
 
-        wxWindow* window = const_cast<wxWindow*>(win);
         if ( ppuX > 0 )
-            best.x = minSize.x + wxSystemSettings::GetMetric(wxSYS_VSCROLL_X, window);
+            best.x = minSize.x + wxSystemSettings::GetMetric(wxSYS_VSCROLL_X, win);
 
         if ( ppuY > 0 )
-            best.y = minSize.y + wxSystemSettings::GetMetric(wxSYS_HSCROLL_Y, window);
+            best.y = minSize.y + wxSystemSettings::GetMetric(wxSYS_HSCROLL_Y, win);
     }
 
     return best;
diff --git a/src/gtk/settings.cpp b/src/gtk/settings.cpp
index d4d1eccae8..a3868eb217 100644
--- a/src/gtk/settings.cpp
+++ b/src/gtk/settings.cpp
@@ -839,7 +839,7 @@ static GtkSettings *GetSettingsForWindowScreen(GdkWindow *window)
                   : gtk_settings_get_default();
 }
 
-static int GetBorderWidth(wxSystemMetric index, wxWindow* win)
+static int GetBorderWidth(wxSystemMetric index, const wxWindow* win)
 {
     if (win->m_wxwindow)
     {
@@ -912,7 +912,7 @@ static int GetScrollbarWidth()
     return width;
 }
 
-int wxSystemSettingsNative::GetMetric( wxSystemMetric index, wxWindow* win )
+int wxSystemSettingsNative::GetMetric( wxSystemMetric index, const wxWindow* win )
 {
     GdkWindow *window = NULL;
     if (win)
diff --git a/src/gtk1/settings.cpp b/src/gtk1/settings.cpp
index 94fbb80bc2..d44a0d65c0 100644
--- a/src/gtk1/settings.cpp
+++ b/src/gtk1/settings.cpp
@@ -358,7 +358,7 @@ wxFont wxSystemSettingsNative::GetFont( wxSystemFont index )
 }
 
 int
-wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
+wxSystemSettingsNative::GetMetric(wxSystemMetric index, const wxWindow* WXUNUSED(win))
 {
     switch (index)
     {
diff --git a/src/motif/settings.cpp b/src/motif/settings.cpp
index 11fd4e7098..d49d13ce7f 100644
--- a/src/motif/settings.cpp
+++ b/src/motif/settings.cpp
@@ -196,7 +196,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 }
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, const wxWindow* WXUNUSED(win))
 {
     int return_value = 0;
 
diff --git a/src/msw/settings.cpp b/src/msw/settings.cpp
index 9cdc03be3c..fc1783c1ac 100644
--- a/src/msw/settings.cpp
+++ b/src/msw/settings.cpp
@@ -262,7 +262,7 @@ static const int gs_metricsMap[] =
 };
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* win)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, const wxWindow* win)
 {
     wxCHECK_MSG( index > 0 && (size_t)index < WXSIZEOF(gs_metricsMap), 0,
                  wxT("invalid metric") );
diff --git a/src/osx/cocoa/settings.mm b/src/osx/cocoa/settings.mm
index fc39244e18..faa1336cc5 100644
--- a/src/osx/cocoa/settings.mm
+++ b/src/osx/cocoa/settings.mm
@@ -217,7 +217,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 // ----------------------------------------------------------------------------
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow *WXUNUSED(win))
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, const wxWindow* WXUNUSED(win))
 {
     int value;
 
diff --git a/src/osx/iphone/settings.mm b/src/osx/iphone/settings.mm
index 807e63b0c8..ae2b8f2da8 100644
--- a/src/osx/iphone/settings.mm
+++ b/src/osx/iphone/settings.mm
@@ -155,7 +155,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 // ----------------------------------------------------------------------------
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow *WXUNUSED(win))
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, const wxWindow* WXUNUSED(win))
 {
     int value;
 
diff --git a/src/qt/settings.cpp b/src/qt/settings.cpp
index 418f7bc25e..f9bad86b12 100644
--- a/src/qt/settings.cpp
+++ b/src/qt/settings.cpp
@@ -163,7 +163,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 
 }
 
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow * WXUNUSED(win))
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, const wxWindow* WXUNUSED(win))
 {
     switch (index)
     {
diff --git a/src/stc/PlatWX.cpp b/src/stc/PlatWX.cpp
index 4a83e12e8c..6ed02faaff 100644
--- a/src/stc/PlatWX.cpp
+++ b/src/stc/PlatWX.cpp
@@ -2718,8 +2718,7 @@ PRectangle wxSTCListBox::GetDesiredRect() const
 
     // Add space for a scrollbar if needed.
     if ( count > desiredVisibleRows )
-        maxw += wxSystemSettings::GetMetric(wxSYS_VSCROLL_X,
-            const_cast<wxWindow*>(wxDynamicCast(this, wxWindow)));
+        maxw += wxSystemSettings::GetMetric(wxSYS_VSCROLL_X, this);
 
     // Add borders.
     maxw += 2 * m_borderSize;
diff --git a/src/univ/settingsuniv.cpp b/src/univ/settingsuniv.cpp
index bf7743be2f..ad4210bf30 100644
--- a/src/univ/settingsuniv.cpp
+++ b/src/univ/settingsuniv.cpp
@@ -96,7 +96,7 @@ wxColour wxSystemSettings::GetColour(wxSystemColour index)
     return wxTheme::Get()->GetColourScheme()->Get(col);
 }
 
-int wxSystemSettings::GetMetric(wxSystemMetric index, wxWindow *win)
+int wxSystemSettings::GetMetric(wxSystemMetric index, const wxWindow* win)
 {
     switch ( index )
     {
diff --git a/src/x11/settings.cpp b/src/x11/settings.cpp
index c65654705f..5e606548bd 100644
--- a/src/x11/settings.cpp
+++ b/src/x11/settings.cpp
@@ -56,7 +56,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 }
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, const wxWindow* WXUNUSED(win))
 {
     switch ( index)
     {