diff --git a/examples/riot/pkg_libcoap/Makefile b/examples/riot/pkg_libcoap/Makefile
index 59126c4d..5ebd916b 100644
--- a/examples/riot/pkg_libcoap/Makefile
+++ b/examples/riot/pkg_libcoap/Makefile
@@ -1,7 +1,7 @@
 PKG_NAME=libcoap
 PKG_URL=https://github.com/obgm/libcoap
 # develop branch as of 20th April 2026
-PKG_VERSION=783b5317caf30397df392228d67969af579fa03b
+PKG_VERSION=86b778167a554bd4add3b9282893df1fc22c2366
 PKG_LICENSE=BSD-2-Clause
 
 LIBCOAP_BUILD_DIR=$(BINDIR)/pkg/$(PKG_NAME)
diff --git a/src/coap_debug.c b/src/coap_debug.c
index 37cd2921..7c74a39b 100644
--- a/src/coap_debug.c
+++ b/src/coap_debug.c
@@ -1062,7 +1062,7 @@ no_more:
         if (exp) {
           snprintf((char *)&buf, sizeof(buf), "%s", exp);
         } else {
-          snprintf((char *)&buf, sizeof(buf), "(%u)", value);
+          snprintf((char *)&buf, sizeof(buf), "(%" PRIu32 ")", value);
         }
         buf_len = strlen((char *)buf);
         break;
diff --git a/src/coap_pdu.c b/src/coap_pdu.c
index e51a6cfb..6228d068 100644
--- a/src/coap_pdu.c
+++ b/src/coap_pdu.c
@@ -307,7 +307,8 @@ coap_pdu_duplicate_lkd(const coap_pdu_t *old_pdu,
           }
         } else {
           coap_delete_pdu_lkd(pdu);
-          coap_log_info("coap_pdu_duplicate: Uri-Path-Abbrev value %u not known for fallback\n", value);
+          coap_log_info("coap_pdu_duplicate: Uri-Path-Abbrev value %" PRIu32 " not known for fallback\n",
+                        value);
           return NULL;
         }
       } else {