   * of files at once by typing "pngtest -m file1.png file2.png ..."
   */
 
-+#if defined MACOSX || defined IOS
++#if defined MACOSX || defined IOS || defined ANDROID
  #include "zlib.h"
 +#else
 +#include <external/zlib/zlib.h>

 #endif

-#include "zlib.h"   /* For crc32 */
+#if defined MACOSX || defined IOS
+#include "zlib.h"
+#else
+#include <external/zlib/zlib.h>

  * data in PNG files.
  */
+/* WTF, surely this should depend explicitly on whether using the system or
+ * internal zlib, not on OS... But yeah, so maybe MacOSX, iOS and Android are the only OSes for which
+ * we use a system zlib but internal libpng, at least by default.
+ */
+#if defined MACOSX || defined IOS || defined ANDROID
 #include "zlib.h"
+#else
+#include <external/zlib/zlib.h>
