diff --git a/openbsc/src/nat/bsc_nat.c b/openbsc/src/nat/bsc_nat.c
index 2ff06d7..734606b 100644
--- a/openbsc/src/nat/bsc_nat.c
+++ b/openbsc/src/nat/bsc_nat.c
@@ -225,6 +225,9 @@
 		default:
 			goto exit;
 		}
+
+		if (!con)
+			LOGP(DNAT, LOGL_ERROR, "Unknown connection for msg type: 0x%x.\n", parsed->sccp_type);
 	}
 
 	talloc_free(parsed);