diff --git a/sys/include/net/nanocoap.h b/sys/include/net/nanocoap.h
index 3605d9b12a..9c26c474e2 100644
--- a/sys/include/net/nanocoap.h
+++ b/sys/include/net/nanocoap.h
@@ -1935,7 +1935,7 @@ ssize_t coap_block2_build_reply(coap_pkt_t *pkt, unsigned code,
  *
  * @returns      length of resulting header
  */
-ssize_t coap_build_hdr(coap_hdr_t *hdr, unsigned type, uint8_t *token,
+ssize_t coap_build_hdr(coap_hdr_t *hdr, unsigned type, const void *token,
                        size_t token_len, unsigned code, uint16_t id);
 
 /**
diff --git a/sys/net/application_layer/nanocoap/nanocoap.c b/sys/net/application_layer/nanocoap/nanocoap.c
index 0636ba3fde..b7b4694b92 100644
--- a/sys/net/application_layer/nanocoap/nanocoap.c
+++ b/sys/net/application_layer/nanocoap/nanocoap.c
@@ -683,7 +683,7 @@ ssize_t coap_build_reply(coap_pkt_t *pkt, unsigned code,
     return len;
 }
 
-ssize_t coap_build_hdr(coap_hdr_t *hdr, unsigned type, uint8_t *token,
+ssize_t coap_build_hdr(coap_hdr_t *hdr, unsigned type, const void *token,
                        size_t token_len, unsigned code, uint16_t id)
 {
     assert(!(type & ~0x3));