diff --git a/docs/changes.txt b/docs/changes.txt
index e19929f7fe..aa9cfbb8c5 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -603,6 +603,7 @@ wxMSW:
 
 wxOSX:
 
+- Fix conversion of wxBitmap to wxImage in 64 bit builds.
 - Fix wxFileDialog::GetFilterIndex() for file open dialogs (phsilva).
 
 
diff --git a/src/osx/core/bitmap.cpp b/src/osx/core/bitmap.cpp
index eff226cd14..c1bf6b7113 100644
--- a/src/osx/core/bitmap.cpp
+++ b/src/osx/core/bitmap.cpp
@@ -1422,13 +1422,12 @@ wxImage wxBitmap::ConvertToImage() const
     for (int yy = 0; yy < height; yy++ , sourcestart += M_BITMAPDATA->GetBytesPerRow() , mask += maskBytesPerRow )
     {
         unsigned char * maskp = mask ;
-        unsigned char * source = sourcestart;
+        const wxUint32 * source = (wxUint32*)sourcestart;
         unsigned char a, r, g, b;
-        long color;
 
         for (int xx = 0; xx < width; xx++)
         {
-            color = *((long*) source) ;
+            const wxUint32 color = *source++;
 #ifdef WORDS_BIGENDIAN
             a = ((color&0xFF000000) >> 24) ;
             r = ((color&0x00FF0000) >> 16) ;
@@ -1470,7 +1469,6 @@ wxImage wxBitmap::ConvertToImage() const
             data[index + 2] = b ;
 
             index += 3;
-            source += 4 ;
         }
     }