diff --git a/include/coap3/coap_pdu_internal.h b/include/coap3/coap_pdu_internal.h
index f112ac21..df2aa6d6 100644
--- a/include/coap3/coap_pdu_internal.h
+++ b/include/coap3/coap_pdu_internal.h
@@ -102,6 +102,9 @@
 #define COAP_PDU_IS_REQUEST(pdu)   (!COAP_PDU_IS_EMPTY(pdu) && (pdu)->code < 32)
 #define COAP_PDU_IS_RESPONSE(pdu)  ((pdu)->code >= 64 && (pdu)->code < 224)
 #define COAP_PDU_IS_SIGNALING(pdu) ((pdu)->code >= 224)
+#define COAP_PDU_IS_PING(pdu)      ((COAP_PDU_IS_EMPTY(pdu) && \
+                                     ((pdu)->type == COAP_MESSAGE_CON)) || \
+                                    ((pdu)->code == COAP_SIGNALING_CODE_PING))
 
 #define COAP_PDU_MAX_UDP_HEADER_SIZE 4
 #define COAP_PDU_MAX_TCP_HEADER_SIZE 6
diff --git a/src/coap_oscore.c b/src/coap_oscore.c
index eeccaee8..e9c5d0a2 100644
--- a/src/coap_oscore.c
+++ b/src/coap_oscore.c
@@ -271,7 +271,7 @@ coap_oscore_new_pdu_encrypted(coap_session_t *session,
                               coap_pdu_t *pdu,
                               coap_bin_const_t *kid_context,
                               oscore_partial_iv_t send_partial_iv) {
-  uint8_t coap_request = COAP_PDU_IS_REQUEST(pdu);
+  uint8_t coap_request = COAP_PDU_IS_REQUEST(pdu) || COAP_PDU_IS_PING(pdu);
   coap_pdu_code_t code =
       coap_request ? COAP_REQUEST_CODE_POST : COAP_RESPONSE_CODE(204);
   coap_pdu_t *osc_pdu;