diff --git a/openbsc/include/openbsc/gprs_llc.h b/openbsc/include/openbsc/gprs_llc.h
index d54b72e..8cd0c26 100644
--- a/openbsc/include/openbsc/gprs_llc.h
+++ b/openbsc/include/openbsc/gprs_llc.h
@@ -218,6 +218,7 @@
 int gprs_llgmm_assign(struct gprs_llc_llme *llme,
 		      uint32_t old_tlli, uint32_t new_tlli,
 		      enum gprs_ciph_algo alg, const uint8_t *kc);
+int gprs_llgmm_unassign(struct gprs_llc_llme *llme);
 
 int gprs_llc_init(const char *cipher_plugin_path);
 int gprs_llc_vty_init(void);
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 5848a63..5db69dd 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -982,8 +982,7 @@
 	if (ctx)
 		mm_ctx_cleanup_free(ctx, "GPRS ATTACH REJ");
 	else
-		/* TLLI unassignment */
-		gprs_llgmm_assign(llme, llme->tlli, 0xffffffff, GPRS_ALGO_GEA0, NULL);
+		gprs_llgmm_unassign(llme);
 
 	return rc;
 
@@ -1286,11 +1285,8 @@
 	if (mmctx)
 		mm_ctx_cleanup_free(mmctx, "GPRS RA UPDATE REJ");
 	else {
-		if (llme) {
-			/* TLLI unassignment */
-			gprs_llgmm_assign(llme, llme->tlli, 0xffffffff,
-					  GPRS_ALGO_GEA0, NULL);
-		}
+		if (llme)
+			gprs_llgmm_unassign(llme);
 	}
 
 	return rc;
@@ -1323,17 +1319,13 @@
 		/* 4.7.10 */
 		if (gh->msg_type == GSM48_MT_GMM_STATUS) {
 			/* TLLI unassignment */
-			gprs_llgmm_assign(llme, llme->tlli, 0xffffffff,
-					  GPRS_ALGO_GEA0, NULL);
+			gprs_llgmm_unassign(llme);
 			return 0;
 		}
 
 		/* Don't reply or establish a LLME on DETACH_ACK */
-		if (gh->msg_type == GSM48_MT_GMM_DETACH_ACK) {
-			/* TLLI unassignment */
-			return gprs_llgmm_assign(llme, llme->tlli, 0xffffffff,
-						 GPRS_ALGO_GEA0, NULL);
-		}
+		if (gh->msg_type == GSM48_MT_GMM_DETACH_ACK)
+			return gprs_llgmm_unassign(llme);
 
 		gprs_llgmm_reset(llme);
 
@@ -1343,8 +1335,7 @@
 			rc = gsm48_rx_gmm_det_req(NULL, msg);
 
 			/* TLLI unassignment */
-			gprs_llgmm_assign(llme, llme->tlli, 0xffffffff,
-					  GPRS_ALGO_GEA0, NULL);
+			gprs_llgmm_unassign(llme);
 			return rc;
 		}
 
@@ -1352,8 +1343,7 @@
 		rc = sgsn_force_reattach_oldmsg(msg);
 
 		/* TLLI unassignment */
-		gprs_llgmm_assign(llme, llme->tlli, 0xffffffff,
-				  GPRS_ALGO_GEA0, NULL);
+		gprs_llgmm_unassign(llme);
 		return rc;
 	}
 
diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c
index 71178c9..64d22b3 100644
--- a/openbsc/src/gprs/gprs_llc.c
+++ b/openbsc/src/gprs/gprs_llc.c
@@ -745,6 +745,13 @@
 	return 0;
 }
 
+/* TLLI unassignment */
+int gprs_llgmm_unassign(struct gprs_llc_llme *llme)
+{
+	return gprs_llgmm_assign(llme, llme->tlli, 0xffffffff, GPRS_ALGO_GEA0,
+				 NULL);
+}
+
 /* Chapter 7.2.1.2 LLGMM-RESET.req */
 int gprs_llgmm_reset(struct gprs_llc_llme *llme)
 {
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index 8f9f453..98439de 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -770,7 +770,7 @@
 	/* No MM context found */
 	LOGP(DGPRS, LOGL_INFO, "Deleting orphaned LLME, TLLI 0x%08x\n",
 	     llme->tlli);
-	gprs_llgmm_assign(llme, llme->tlli, 0xffffffff, GPRS_ALGO_GEA0, NULL);
+	gprs_llgmm_unassign(llme);
 }
 
 static void sgsn_llme_check_cb(void *data_)
diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index f425c33..d568807 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -222,7 +222,7 @@
 	OSMO_ASSERT(count(gprs_llme_list()) == 1);
 
 	/* unassign which should delete it*/
-	gprs_llgmm_assign(lle->llme, lle->llme->tlli, 0xffffffff, GPRS_ALGO_GEA0, NULL);
+	gprs_llgmm_unassign(lle->llme);
 
 	/* Check that everything was cleaned up */
 	OSMO_ASSERT(count(gprs_llme_list()) == 0);