--- ppmtoansi-0.4.old/pta.c
+++ ppmtoansi-0.4/pta.c
@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <math.h>
 #include <string.h>
-#include "ppm.h"
+#include <netpbm/ppm.h>
 
 double red_scale = 0.3;
 double green_scale = 0.59;