diff --git a/lib/hexdump.c b/lib/hexdump.c
index 16f2e29..bd5edae 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -189,7 +189,7 @@
  * rowsize of 16, groupsize of 1, and ASCII output included.
  */
 void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
-			void *buf, size_t len)
+			const void *buf, size_t len)
 {
 	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
 			buf, len, 1);