diff --git a/include/wx/mac/dc.h b/include/wx/mac/dc.h
index 9bdbaaf9f1..fcb02f65e9 100644
--- a/include/wx/mac/dc.h
+++ b/include/wx/mac/dc.h
@@ -51,7 +51,7 @@ extern int wxPageNumber;
 class WXDLLEXPORT wxMacPortSetter
 {
 public :
-	wxMacPortSetter( wxDC* dc ) ;
+	wxMacPortSetter( const wxDC* dc ) ;
 	~wxMacPortSetter() ;
 private :
 	AGAPortHelper m_ph ;
diff --git a/src/mac/carbon/dc.cpp b/src/mac/carbon/dc.cpp
index 1a21092f94..8285afd1c6 100644
--- a/src/mac/carbon/dc.cpp
+++ b/src/mac/carbon/dc.cpp
@@ -85,7 +85,7 @@ wxDC::wxDC()
     m_brush = *wxWHITE_BRUSH;
 };
 
-wxMacPortSetter::wxMacPortSetter( wxDC* dc ) :
+wxMacPortSetter::wxMacPortSetter( const wxDC* dc ) :
 	m_ph( dc->m_macPort ) 
 {
 	wxASSERT( dc->Ok() ) ;
diff --git a/src/mac/dc.cpp b/src/mac/dc.cpp
index 1a21092f94..8285afd1c6 100644
--- a/src/mac/dc.cpp
+++ b/src/mac/dc.cpp
@@ -85,7 +85,7 @@ wxDC::wxDC()
     m_brush = *wxWHITE_BRUSH;
 };
 
-wxMacPortSetter::wxMacPortSetter( wxDC* dc ) :
+wxMacPortSetter::wxMacPortSetter( const wxDC* dc ) :
 	m_ph( dc->m_macPort ) 
 {
 	wxASSERT( dc->Ok() ) ;