diff --git a/src/include/ip_checksum.h b/src/include/ip_checksum.h
index a1e0ffabd1..f6ef560057 100644
--- a/src/include/ip_checksum.h
+++ b/src/include/ip_checksum.h
@@ -1,5 +1,5 @@
 #ifndef IP_CHECKSUM_H
 #define IP_CHECKSUM_H
-unsigned long compute_ip_checksum(void *addr, unsigned long length);
+unsigned long compute_ip_checksum(const void *addr, unsigned long length);
 unsigned long add_ip_checksums(unsigned long offset, unsigned long sum, unsigned long new);
 #endif /* IP_CHECKSUM_H */
diff --git a/src/lib/compute_ip_checksum.c b/src/lib/compute_ip_checksum.c
index 58a6bf1ee4..347b83f220 100644
--- a/src/lib/compute_ip_checksum.c
+++ b/src/lib/compute_ip_checksum.c
@@ -1,9 +1,9 @@
 #include <stdint.h>
 #include <ip_checksum.h>
 
-unsigned long compute_ip_checksum(void *addr, unsigned long length)
+unsigned long compute_ip_checksum(const void *addr, unsigned long length)
 {
-	uint8_t *ptr;
+	const uint8_t *ptr;
 	volatile union {
 		uint8_t  byte[2];
 		uint16_t word;