diff --git a/src/osx/carbon/cursor.cpp b/src/osx/carbon/cursor.cpp
index 54b1f8ef1d..995e08b846 100644
--- a/src/osx/carbon/cursor.cpp
+++ b/src/osx/carbon/cursor.cpp
@@ -239,7 +239,7 @@ wxCursorRefData::wxCursorRefData()
 #endif
 }
 
-wxCursorRefData::wxCursorRefData(const wxCursorRefData& cursor)
+wxCursorRefData::wxCursorRefData(const wxCursorRefData& cursor) : wxGDIRefData()
 {
     m_hCursor = NULL;
 
diff --git a/src/osx/carbon/font.cpp b/src/osx/carbon/font.cpp
index 9c81bd9fe6..5a1b9bae8b 100644
--- a/src/osx/carbon/font.cpp
+++ b/src/osx/carbon/font.cpp
@@ -175,7 +175,7 @@ public:
 
 #define M_FONTDATA ((wxFontRefData*)m_refData)
 
-wxFontRefData::wxFontRefData(const wxFontRefData& data)
+wxFontRefData::wxFontRefData(const wxFontRefData& data) : wxGDIRefData()
 {
     Init();
     m_info = data.m_info;
diff --git a/src/osx/core/bitmap.cpp b/src/osx/core/bitmap.cpp
index 72ba979c41..8ef77049d1 100644
--- a/src/osx/core/bitmap.cpp
+++ b/src/osx/core/bitmap.cpp
@@ -255,7 +255,7 @@ void wxBitmapRefData::Init()
     m_hasAlpha = false;
 }
 
-wxBitmapRefData::wxBitmapRefData(const wxBitmapRefData &tocopy)
+wxBitmapRefData::wxBitmapRefData(const wxBitmapRefData &tocopy) : wxGDIRefData()
 {
     Init();
     Create(tocopy.m_width, tocopy.m_height, tocopy.m_depth);
@@ -1531,7 +1531,7 @@ wxMask::wxMask()
     Init() ;
 }
 
-wxMask::wxMask(const wxMask &tocopy)
+wxMask::wxMask(const wxMask &tocopy) : wxObject()
 {
     Init();
 
diff --git a/src/osx/palette.cpp b/src/osx/palette.cpp
index a288caa9bd..b0d4aef469 100644
--- a/src/osx/palette.cpp
+++ b/src/osx/palette.cpp
@@ -46,7 +46,7 @@ wxPaletteRefData::wxPaletteRefData()
     m_count = 0;
 }
 
-wxPaletteRefData::wxPaletteRefData(const wxPaletteRefData& data)
+wxPaletteRefData::wxPaletteRefData(const wxPaletteRefData& data) : wxGDIRefData()
 {
     m_count = data.m_count;
     m_palette = new wxColour[m_count];