diff --git a/include/osmocom/gprs/llc/llc_prim.h b/include/osmocom/gprs/llc/llc_prim.h
index c03f396..adcd22f 100644
--- a/include/osmocom/gprs/llc/llc_prim.h
+++ b/include/osmocom/gprs/llc/llc_prim.h
@@ -56,6 +56,7 @@ enum osmo_gprs_llc_ll_prim_type {
 	OSMO_GPRS_LLC_LL_DATA,		/* Req/Ind/Cnf: TLLI, L3-PDU, Ref, QoS, Radio Prio */
 	OSMO_GPRS_LLC_LL_UNITDATA,	/* Req/Ind: TLLI, L3-PDU, QoS, Radio Prio, Ciph, ... */
 	OSMO_GPRS_LLC_LL_STATUS,	/* Ind: TLLI, Cause */
+	OSMO_GPRS_LLC_LL_ASSIGN,	/* Ind: TLLI old, TLLI new; Osmocom specific */
 };
 
 extern const struct value_string osmo_gprs_llc_ll_prim_type_names[];
@@ -214,6 +215,10 @@ struct osmo_gprs_llc_ll_prim {
 		struct {
 			uint8_t cause;
 		} status_ind;
+		/* OSMO_GPRS_LLC_LL_ASSIGN | Ind */
+		struct {
+			uint32_t tlli_new;
+		} assign_ind;
 	};
 };
 
diff --git a/include/osmocom/gprs/llc/llc_private.h b/include/osmocom/gprs/llc/llc_private.h
index 78e6e9f..44d32e2 100644
--- a/include/osmocom/gprs/llc/llc_private.h
+++ b/include/osmocom/gprs/llc/llc_private.h
@@ -297,6 +297,7 @@ struct osmo_gprs_llc_prim *gprs_llc_prim_alloc_ll_xid_ind(uint32_t tlli, enum os
 							  uint8_t *l3_par, unsigned int l3_par_len);
 struct osmo_gprs_llc_prim *gprs_llc_prim_alloc_ll_xid_cnf(uint32_t tlli, enum osmo_gprs_llc_sapi ll_sapi,
 							  uint8_t *l3_par, unsigned int l3_par_len);
+struct osmo_gprs_llc_prim *gprs_llc_prim_alloc_ll_assign_ind(uint32_t old_tlli, uint32_t new_tlli);
 struct osmo_gprs_llc_prim *gprs_llc_prim_alloc_ll_unitdata_ind(
 				uint32_t tlli, enum osmo_gprs_llc_sapi ll_sapi,
 				uint8_t *l3_pdu, size_t l3_pdu_len);
@@ -305,7 +306,7 @@ int gprs_llc_lle_submit_prim_ll_xid_ind(struct gprs_llc_lle *lle,
 int gprs_llc_lle_submit_prim_ll_xid_cnf(struct gprs_llc_lle *lle,
 					const struct gprs_llc_xid_field *xid_field_response_l3,
 					const struct gprs_llc_xid_field *xid_field_request_l3);
-
+int gprs_llc_llme_submit_prim_ll_assign_ind(uint32_t old_tlli, uint32_t new_tlli);
 /* llc_llgmm.c */
 int gprs_llc_prim_llgmm_upper_down(struct osmo_gprs_llc_prim *llc_prim);
 
diff --git a/src/llc/llc_ll.c b/src/llc/llc_ll.c
index a13a7f5..b907299 100644
--- a/src/llc/llc_ll.c
+++ b/src/llc/llc_ll.c
@@ -40,6 +40,7 @@ const struct value_string osmo_gprs_llc_ll_prim_type_names[] = {
 	{ OSMO_GPRS_LLC_LL_DATA,		"DATA" },
 	{ OSMO_GPRS_LLC_LL_UNITDATA,		"UNITDATA" },
 	{ OSMO_GPRS_LLC_LL_STATUS,		"STATUS" },
+	{ OSMO_GPRS_LLC_LL_ASSIGN,		"ASSIGN" },
 	{ 0, NULL }
 };
 
@@ -152,6 +153,17 @@ struct osmo_gprs_llc_prim *gprs_llc_prim_alloc_ll_unitdata_ind(
 	return llc_prim;
 }
 
+/* LL-ASSIGN.ind (MS/SGSN): Osmocom specific, used to inform TLLI update LLC->SNDCP */
+struct osmo_gprs_llc_prim *gprs_llc_prim_alloc_ll_assign_ind(uint32_t old_tlli, uint32_t new_tlli)
+{
+	struct osmo_gprs_llc_prim *llc_prim;
+	llc_prim = llc_prim_ll_alloc(OSMO_GPRS_LLC_LL_ASSIGN, PRIM_OP_INDICATION, 0);
+	llc_prim->ll.tlli = old_tlli;
+	llc_prim->ll.sapi = OSMO_GPRS_LLC_SAPI_SNDCP3; /* any SNDCP SAPI is good */
+	llc_prim->ll.assign_ind.tlli_new = new_tlli;
+	return llc_prim;
+}
+
 /********************************
  * Handling to upper layers:
  ********************************/
@@ -192,6 +204,16 @@ int gprs_llc_lle_submit_prim_ll_xid_cnf(struct gprs_llc_lle *lle,
 
 	return gprs_llc_prim_call_up_cb(llc_prim_tx);
 }
+
+int gprs_llc_llme_submit_prim_ll_assign_ind(uint32_t old_tlli, uint32_t new_tlli)
+{
+	struct osmo_gprs_llc_prim *llc_prim_tx;
+	llc_prim_tx = gprs_llc_prim_alloc_ll_assign_ind(old_tlli, new_tlli);
+	OSMO_ASSERT(llc_prim_tx);
+
+	return gprs_llc_prim_call_up_cb(llc_prim_tx);
+}
+
 /********************************
  * Handling from upper layers:
  ********************************/
diff --git a/src/llc/llc_llgmm.c b/src/llc/llc_llgmm.c
index d85a30e..f33d6de 100644
--- a/src/llc/llc_llgmm.c
+++ b/src/llc/llc_llgmm.c
@@ -207,6 +207,9 @@ static int llc_prim_handle_llgmm_assign_req(struct osmo_gprs_llc_prim *llc_prim)
 		llme->old_tlli = old_tlli;
 		llme->tlli = new_tlli;
 		llme->state = OSMO_GPRS_LLC_LLMS_ASSIGNED;
+		/* Inform SNDCP about the TLLI change so it can update it too: */
+		if (old_tlli != new_tlli)
+			gprs_llc_llme_submit_prim_ll_assign_ind(old_tlli, new_tlli);
 	} else if (old_tlli != TLLI_UNASSIGNED && new_tlli == TLLI_UNASSIGNED) {
 		/* TLLI Unassignment 8.3.3) */
 		llme->tlli = llme->old_tlli = 0;
diff --git a/tests/llc/llc_prim_test.c b/tests/llc/llc_prim_test.c
index bcba783..b9e2e0e 100644
--- a/tests/llc/llc_prim_test.c
+++ b/tests/llc/llc_prim_test.c
@@ -48,9 +48,17 @@ int test_llc_prim_up_cb(struct osmo_gprs_llc_prim *llc_prim, void *user_data)
 		printf("%s(): Rx %s TLLI=0x%08x\n", __func__, pdu_name, llc_prim->llgmm.tlli);
 		break;
 	case OSMO_GPRS_LLC_SAP_LL:
-		printf("%s(): Rx %s TLLI=0x%08x SAPI=%s l3=[%s]\n", __func__, pdu_name,
-		       llc_prim->ll.tlli, osmo_gprs_llc_sapi_name(llc_prim->ll.sapi),
-		       osmo_hexdump(llc_prim->ll.l3_pdu, llc_prim->ll.l3_pdu_len));
+		switch (OSMO_PRIM_HDR(&llc_prim->oph)) {
+		case OSMO_PRIM(OSMO_GPRS_LLC_LL_ASSIGN, PRIM_OP_INDICATION):
+			printf("%s(): Rx %s TLLI=0x%08x NEW_TLLI=x%08x\n", __func__, pdu_name,
+			       llc_prim->ll.tlli, llc_prim->ll.assign_ind.tlli_new);
+			break;
+		default:
+			printf("%s(): Rx %s TLLI=0x%08x SAPI=%s l3=[%s]\n", __func__, pdu_name,
+			       llc_prim->ll.tlli, osmo_gprs_llc_sapi_name(llc_prim->ll.sapi),
+			       osmo_hexdump(llc_prim->ll.l3_pdu, llc_prim->ll.l3_pdu_len));
+			break;
+		}
 		break;
 	default:
 		printf("%s(): Unexpected Rx %s\n", __func__, pdu_name);