diff --git a/src/heightmap.cpp b/src/heightmap.cpp
--- a/src/heightmap.cpp
+++ b/src/heightmap.cpp
@@ -32,7 +32,7 @@ static inline byte RGBToGrayscale(byte r
 
 #ifdef WITH_PNG
 
-#include "png.h"
+#include <png.h>
 
 /**
  * The PNG Heightmap loader.