diff --git a/src/coap_net.c b/src/coap_net.c
index fcf9b7ff..2f2406ac 100644
--- a/src/coap_net.c
+++ b/src/coap_net.c
@@ -1096,7 +1096,7 @@ coap_send(coap_session_t *session, coap_pdu_t *pdu) {
   }
 
   /* A lot of the reliable code assumes type is CON */
-  if (COAP_PROTO_RELIABLE(session->proto) && pdu->type == COAP_MESSAGE_NON)
+  if (COAP_PROTO_RELIABLE(session->proto) && pdu->type != COAP_MESSAGE_CON)
     pdu->type = COAP_MESSAGE_CON;
 
 #if COAP_OSCORE_SUPPORT
diff --git a/src/coap_pdu.c b/src/coap_pdu.c
index afe445c8..56cb55b6 100644
--- a/src/coap_pdu.c
+++ b/src/coap_pdu.c
@@ -1435,6 +1435,11 @@ coap_pdu_encode_header(coap_pdu_t *pdu, coap_proto_t proto) {
       coap_log_warn("coap_pdu_encode_header: corrupted PDU\n");
       return 0;
     }
+
+    /* A lot of the reliable code assumes type is CON */
+    if (pdu->type != COAP_MESSAGE_CON)
+      pdu->type = COAP_MESSAGE_CON;
+
     if (proto == COAP_PROTO_WS || proto == COAP_PROTO_WSS)
       len = 0;
     else