diff --git a/toxcore/util.c b/toxcore/util.c
index 46b33400..e3bfac4c 100644
--- a/toxcore/util.c
+++ b/toxcore/util.c
@@ -58,12 +58,12 @@ int is_timeout(uint64_t timestamp, uint64_t timeout)
 
 
 /* id functions */
-bool id_equal(uint8_t *dest, uint8_t *src)
+bool id_equal(const uint8_t *dest, const uint8_t *src)
 {
     return memcmp(dest, src, CLIENT_ID_SIZE) == 0;
 }
 
-uint32_t id_copy(uint8_t *dest, uint8_t *src)
+uint32_t id_copy(uint8_t *dest, const uint8_t *src)
 {
     memcpy(dest, src, CLIENT_ID_SIZE);
     return CLIENT_ID_SIZE;
diff --git a/toxcore/util.h b/toxcore/util.h
index 71c2f5c7..74348c11 100644
--- a/toxcore/util.h
+++ b/toxcore/util.h
@@ -36,8 +36,8 @@ int is_timeout(uint64_t timestamp, uint64_t timeout);
 
 
 /* id functions */
-bool id_equal(uint8_t *dest, uint8_t *src);
-uint32_t id_copy(uint8_t *dest, uint8_t *src); /* return value is CLIENT_ID_SIZE */
+bool id_equal(const uint8_t *dest, const uint8_t *src);
+uint32_t id_copy(uint8_t *dest, const uint8_t *src); /* return value is CLIENT_ID_SIZE */
 
 void host_to_net(uint8_t *num, uint16_t numbytes);
 #define net_to_host(x, y) host_to_net(x, y)