diff --git a/openbsc/src/bsc_mgcp.c b/openbsc/src/bsc_mgcp.c
index 66c8d74..a16c03c 100644
--- a/openbsc/src/bsc_mgcp.c
+++ b/openbsc/src/bsc_mgcp.c
@@ -238,8 +238,10 @@
 	}
 
 	/* do not forward aynthing... maybe there is a packet from the bts */
-	if (endp->ci == CI_UNUSED)
+	if (endp->ci == CI_UNUSED) {
+		DEBUGP(DMGCP, "Unknown message on endpoint: 0x%x\n", ENDPOINT_NUMBER(endp));
 		return -1;
+	}
 
 	/*
 	 * Figure out where to forward it to. This code assumes that we