diff --git a/libs/openzap/src/isdn/Q931mes.c b/libs/openzap/src/isdn/Q931mes.c
index 497e6c1a94..d1e2a85112 100644
--- a/libs/openzap/src/isdn/Q931mes.c
+++ b/libs/openzap/src/isdn/Q931mes.c
@@ -1194,6 +1194,8 @@ L3INT Q931Umes_Setup(Q931_TrunkInfo_t *pTrunk, L3UCHAR *IBuf, Q931mes_Generic *m
 		switch(IBuf[IOff])
 		{
 		case Q931ie_SENDING_COMPLETE:
+			IOff++;
+			break;
 		case Q931ie_BEARER_CAPABILITY:
 		case Q931ie_CHANNEL_IDENTIFICATION:
 		case Q931ie_PROGRESS_INDICATOR: