diff --git a/pony_spi.c b/pony_spi.c
index 6ce467e..fb90a33 100644
--- a/pony_spi.c
+++ b/pony_spi.c
@@ -22,6 +22,7 @@
  */
 
 #include <stdlib.h>
+#include <strings.h>
 #include <string.h>
 
 #include "flash.h"