diff --git a/openbsc/src/input/dahdi.c b/openbsc/src/input/dahdi.c
index 08bd1e0..c086954 100644
--- a/openbsc/src/input/dahdi.c
+++ b/openbsc/src/input/dahdi.c
@@ -169,7 +169,8 @@
 		return 0;
 	}
 
-	lapd_transmit(e1i_ts->driver.dahdi.lapd, sign_link->tei, msg->data, msg->len);
+	lapd_transmit(e1i_ts->driver.dahdi.lapd, sign_link->tei,
+		      sign_link->sapi, msg->data, msg->len);
 	msgb_free(msg);
 
 	/* set tx delay timer for next event */
diff --git a/openbsc/src/input/lapd.c b/openbsc/src/input/lapd.c
index de0d5a5..8aa71e2 100644
--- a/openbsc/src/input/lapd.c
+++ b/openbsc/src/input/lapd.c
@@ -97,7 +97,6 @@
 	struct llist_head list;
 
 	uint8_t tei;
-	uint8_t sapi;
 	/* A valid N(R) value is one that is in the range V(A) ≤ N(R) ≤ V(S). */
 	int vs;			/* next to be transmitted */
 	int va;			/* last acked by peer */
@@ -456,7 +455,7 @@
 	return NULL;
 };
 
-void lapd_transmit(struct lapd_instance *li, uint8_t tei,
+void lapd_transmit(struct lapd_instance *li, uint8_t tei, uint8_t sapi,
 		   uint8_t *data, unsigned int len)
 {
 	//printf("lapd_transmit %d, %d\n", tei, len);
@@ -475,8 +474,8 @@
 	memmove(buf + 4, data, len);
 	len += 4;
 
-	buf[0] = (teip->sapi << 2) | (li->network_side ? 2 : 0);
-	buf[1] = (teip->tei << 1) | 1;
+	buf[0] = (sapi << 2) | (li->network_side ? 2 : 0);
+	buf[1] = (tei << 1) | 1;
 	buf[2] = (LAPD_NS(teip) << 1);
 	buf[3] = (LAPD_NR(teip) << 1) | 0;
 
diff --git a/openbsc/src/input/lapd.h b/openbsc/src/input/lapd.h
index f79d84f..1661af7 100644
--- a/openbsc/src/input/lapd.h
+++ b/openbsc/src/input/lapd.h
@@ -29,7 +29,8 @@
 extern uint8_t *lapd_receive(struct lapd_instance *li, uint8_t *data, unsigned int len,
 			     int *ilen, lapd_mph_type *prim);
 
-extern void lapd_transmit(struct lapd_instance *li, uint8_t tei, uint8_t *data, unsigned int len);
+extern void lapd_transmit(struct lapd_instance *li, uint8_t tei, uint8_t sapi,
+			  uint8_t *data, unsigned int len);
 
 struct lapd_instance *lapd_instance_alloc(void (*tx_cb)(uint8_t *data, int len,
 							void *cbdata), void *cbdata);