--- a/ppm.c
+++ b/ppm.c
@@ -225,7 +225,7 @@
     }
 
 
-    sprintf(header, "P6\n" FMT_INT32 " " FMT_INT32 "\n%ld\n", im->width,
+    sprintf(header, "P6\n%d %d\n%ld\n", im->width,
             im->height, 255L);
 
     count = strlen(header);