diff --git a/include/wx/peninfobase.h b/include/wx/peninfobase.h
index 33a0c40674..9fb499dbe4 100644
--- a/include/wx/peninfobase.h
+++ b/include/wx/peninfobase.h
@@ -79,7 +79,7 @@ public:
     T& Stipple(const wxBitmap& stipple)
         { m_stipple = stipple; m_style = wxPENSTYLE_STIPPLE; return This(); }
     T& Dashes(int nb_dashes, const wxDash *dash)
-        { m_nb_dashes = nb_dashes; m_dash = (wxDash *)dash; return This(); }
+        { m_nb_dashes = nb_dashes; m_dash = const_cast<wxDash*>(dash); return This(); }
     T& Join(wxPenJoin join)
         { m_join = join; return This(); }
     T& Cap(wxPenCap cap)
diff --git a/src/gtk/pen.cpp b/src/gtk/pen.cpp
index e5976eb85a..3db6ead31e 100644
--- a/src/gtk/pen.cpp
+++ b/src/gtk/pen.cpp
@@ -53,7 +53,7 @@ public:
         m_joinStyle = info.GetJoin();
         m_capStyle = info.GetCap();
         m_colour = info.GetColour();
-        m_countDashes = info.GetDashes((wxDash**)&m_dash);
+        m_countDashes = info.GetDashes(const_cast<wxDash**>(&m_dash));
     }
 
     bool operator == (const wxPenRefData& data) const