diff --git a/src/eir.c b/src/eir.c
index 525fa80..d14f2a0 100644
--- a/src/eir.c
+++ b/src/eir.c
@@ -306,7 +306,7 @@ static void eir_generate_uuid128(sdp_list_t *list, uint8_t *ptr,
 }
 
 int eir_create_oob(const bdaddr_t *addr, const char *name, uint32_t cod,
-			uint8_t *hash, uint8_t *randomizer,
+			const uint8_t *hash, const uint8_t *randomizer,
 			uint16_t did_vendor, uint16_t did_product,
 			uint16_t did_version, uint16_t did_source,
 			sdp_list_t *uuids, uint8_t *data)
diff --git a/src/eir.h b/src/eir.h
index 41b8d02..72953eb 100644
--- a/src/eir.h
+++ b/src/eir.h
@@ -54,7 +54,7 @@ void eir_data_free(struct eir_data *eir);
 int eir_parse(struct eir_data *eir, const uint8_t *eir_data, uint8_t eir_len);
 int eir_parse_oob(struct eir_data *eir, uint8_t *eir_data, uint16_t eir_len);
 int eir_create_oob(const bdaddr_t *addr, const char *name, uint32_t cod,
-			uint8_t *hash, uint8_t *randomizer,
+			const uint8_t *hash, const uint8_t *randomizer,
 			uint16_t did_vendor, uint16_t did_product,
 			uint16_t did_version, uint16_t did_source,
 			sdp_list_t *uuids, uint8_t *data);