diff -u -r spamprobe-1.4d.orig/src/parser/GifParser.cc spamprobe-1.4d/src/parser/GifParser.cc
--- spamprobe-1.4d.orig/src/parser/GifParser.cc	2013-08-19 09:32:03.637652517 +0900
+++ spamprobe-1.4d/src/parser/GifParser.cc	2013-08-19 09:33:56.728655212 +0900
@@ -99,7 +99,11 @@
 void GifParser::openImage()
 {
   m_nextByteIndex = 0;
+#if GIFLIB_MAJOR >= 5
+  m_gif = DGifOpen(this, readFromBuffer, NULL);
+#else
   m_gif = DGifOpen(this, readFromBuffer);
+#endif
   if (!m_gif) {
     throw runtime_error("open gif failed");
   }
diff -u -r spamprobe-1.4d.orig/src/parser/GifParser.h spamprobe-1.4d/src/parser/GifParser.h
--- spamprobe-1.4d.orig/src/parser/GifParser.h	2013-08-19 09:32:03.638652517 +0900
+++ spamprobe-1.4d/src/parser/GifParser.h	2013-08-19 09:45:07.019487685 +0900
@@ -33,6 +33,7 @@
 #ifndef _GifParser_h
 #define _GifParser_h
 
+#include <stddef.h>
 extern "C" {
 #include <gif_lib.h>
 }