diff --git a/checksum.h b/checksum.h
index 6195810..d0af88e 100644
--- a/checksum.h
+++ b/checksum.h
@@ -18,6 +18,10 @@
 #ifndef __CHECKSUM_H__
 #define __CHECKSUM_H__
 
+#include <stdint.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+
 uint32_t ip_checksum_add(uint32_t current, const void *data, int len);
 uint16_t ip_checksum_finish(uint32_t temp_sum);
 uint16_t ip_checksum(const void *data, int len);