diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index 94a6209..ea11a71 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -1436,6 +1436,7 @@
 			/* Assign lchan */
 			if (!transt->conn) {
 				transt->conn = conn;
+				conn->put_channel = 1;
 			}
 			/* send SETUP request to called party */
 			gsm48_cc_tx_setup(transt, &transt->cc.msg);