diff --git a/src/eap_peer/eap_tnc.c b/src/eap_peer/eap_tnc.c
index c56001528..177d432c1 100644
--- a/src/eap_peer/eap_tnc.c
+++ b/src/eap_peer/eap_tnc.c
@@ -262,7 +262,7 @@ static struct wpabuf * eap_tnc_process(struct eap_sm *sm, void *priv,
 		   "Message Length %u", flags, message_length);
 
 	if (data->state == WAIT_FRAG_ACK) {
-		if (len != 0) {
+		if (len > 1) {
 			wpa_printf(MSG_DEBUG, "EAP-TNC: Unexpected payload in "
 				   "WAIT_FRAG_ACK state");
 			ret->ignore = TRUE;
diff --git a/src/eap_server/eap_tnc.c b/src/eap_server/eap_tnc.c
index 4cb3ecfb0..93f0cf022 100644
--- a/src/eap_server/eap_tnc.c
+++ b/src/eap_server/eap_tnc.c
@@ -453,7 +453,7 @@ static void eap_tnc_process(struct eap_sm *sm, void *priv,
 		   "Message Length %u", flags, message_length);
 
 	if (data->state == WAIT_FRAG_ACK) {
-		if (len != 0) {
+		if (len > 1) {
 			wpa_printf(MSG_DEBUG, "EAP-TNC: Unexpected payload "
 				   "in WAIT_FRAG_ACK state");
 			data->state = FAIL;