--- apng2gif-1.6-src/apng2gif.cpp
+++ apng2gif-1.6-src/apng2gif.cpp
@@ -30,6 +30,7 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <cstring>
 #include <vector>
 #include "png.h"     /* original (unpatched) libpng is ok */
 #include "zlib.h"