diff --git a/src/png/png.c b/src/png/png.c
index 5cfeb4546f..74b3032d7d 100644
--- a/src/png/png.c
+++ b/src/png/png.c
@@ -144,7 +144,7 @@ png_zalloc(voidpf png_ptr, uInt items, uInt size)
 {
    png_uint_32 num_bytes = (png_uint_32)items * size;
    png_voidp ptr;
-   png_structp p=png_ptr;
+   png_structp p=(png_struct*)png_ptr;
    png_uint_32 save_flags=p->flags;
 
    p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
diff --git a/src/png/pngconf.h b/src/png/pngconf.h
index 0f98ff4af8..738a43a44c 100644
--- a/src/png/pngconf.h
+++ b/src/png/pngconf.h
@@ -80,9 +80,9 @@
  * 'Cygwin' defines/defaults:
  *   PNG_BUILD_DLL -- (ignored) building the dll
  *   (no define)   -- (ignored) building an application, linking to the dll
- *   PNG_STATIC    -- (ignored) building the static lib, or building an 
+ *   PNG_STATIC    -- (ignored) building the static lib, or building an
  *                    application that links to the static lib.
- *   ALL_STATIC    -- (ignored) building various static libs, or building an 
+ *   ALL_STATIC    -- (ignored) building various static libs, or building an
  *                    application that links to the static libs.
  * Thus,
  * a cygwin user should define either PNG_BUILD_DLL or PNG_STATIC, and
@@ -95,12 +95,12 @@
  *   PNG_BUILD_DLL
  *   PNG_STATIC
  *   (nothing) == PNG_USE_DLL
- * 
+ *
  * CYGWIN (2002-01-20): The preceding is now obsolete. With the advent
- *   of auto-import in binutils, we no longer need to worry about 
+ *   of auto-import in binutils, we no longer need to worry about
  *   __declspec(dllexport) / __declspec(dllimport) and friends.  Therefore,
  *   we don't need to worry about PNG_STATIC or ALL_STATIC when it comes
- *   to __declspec() stuff.  However, we DO need to worry about 
+ *   to __declspec() stuff.  However, we DO need to worry about
  *   PNG_BUILD_DLL and PNG_STATIC because those change some defaults
  *   such as CONSOLE_IO and whether GLOBAL_ARRAYS are allowed.
  */
@@ -144,8 +144,8 @@
 #        if !defined(PNG_DLL)
 #          define PNG_DLL
 #        endif
-#      endif  
-#    endif  
+#      endif
+#    endif
 #  endif
 #endif
 
@@ -640,7 +640,7 @@
 #  define PNG_EASY_ACCESS_SUPPORTED
 #endif
 
-/* PNG_ASSEMBLER_CODE was enabled by default in version 1.2.0 
+/* PNG_ASSEMBLER_CODE was enabled by default in version 1.2.0
    even when PNG_USE_PNGVCRD or PNG_USE_PNGGCCRD is not defined */
 #if defined(PNG_READ_SUPPORTED) && !defined(PNG_NO_ASSEMBLER_CODE)
 #  ifndef PNG_ASSEMBLER_CODE_SUPPORTED
@@ -1162,7 +1162,7 @@ typedef z_stream FAR *  png_zstreamp;
 #  define PNGAPI __cdecl
 #  undef PNG_IMPEXP
 #  define PNG_IMPEXP
-#endif  
+#endif
 
 /* If you define PNGAPI, e.g., with compiler option "-DPNGAPI=__stdcall",
  * you may get warnings regarding the linkage of png_zalloc and png_zfree.
@@ -1241,6 +1241,20 @@ typedef z_stream FAR *  png_zstreamp;
 #endif
 #endif
 
+#if defined(__VISAGECPP__)
+/* I don't compile with this _System linkage for wxWindows */
+#  ifdef PNGAPI
+#    undef PNGAPI
+#  endif
+#  define PNGAPI _Optlink
+#  define PNG_IMPEXP
+#  define PNG_USE_LOCAL_ARRAYS
+#  ifdef PNG_USE_GLOBAL_ARRAYS
+#    undef PNG_USE_GLOBAL_ARRAYS
+#  endif
+extern const char png_libpng_ver[18];
+#endif
+
 #ifndef PNGAPI
 #  define PNGAPI
 #endif
@@ -1317,7 +1331,7 @@ typedef z_stream FAR *  png_zstreamp;
 #  define PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT  128  /*  >=  */
 #endif
 #ifndef PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT
-#  define PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT  9    /*  >=  */   
+#  define PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT  9    /*  >=  */
 #endif
 
 /* Set this in the makefile for VC++ on Pentium, not here. */