1 files changed, 2 insertions, 1 deletions
diff --git a/lib.h b/lib.h
index bebc1df..1831f5e 100644
--- a/lib.h
+++ b/lib.h
@@ -2,12 +2,13 @@
 #define LIB_H
 
 #include <stdbool.h>
+#include <stdint.h>
 #include <stdlib.h>
 
 typedef struct State
 {
   // Sandpiles
-  unsigned char *data;
+  uint64_t *data;
   size_t dwidth;
 
   size_t window_len;