diff --git a/include/osmocom/sgsn/gprs_gmm.h b/include/osmocom/sgsn/gprs_gmm.h
index 3c93efc..28c96ce 100644
--- a/include/osmocom/sgsn/gprs_gmm.h
+++ b/include/osmocom/sgsn/gprs_gmm.h
@@ -43,4 +43,6 @@
 /* TODO: move extract_subscr_* when gsm48_gmm_authorize() got removed */
 void extract_subscr_msisdn(struct sgsn_mm_ctx *ctx);
 void extract_subscr_hlr(struct sgsn_mm_ctx *ctx);
+
+void pdp_ctx_detach_mm_ctx(struct sgsn_pdp_ctx *pdp);
 #endif /* _GPRS_GMM_H */
diff --git a/src/gprs/gprs_gmm.c b/src/gprs/gprs_gmm.c
index 6a5c5d9..9d8a869 100644
--- a/src/gprs/gprs_gmm.c
+++ b/src/gprs/gprs_gmm.c
@@ -2192,6 +2192,16 @@
 	osmo_timer_del(&pdp->timer);
 }
 
+void pdp_ctx_detach_mm_ctx(struct sgsn_pdp_ctx *pdp)
+{
+	/* Detach from MM context */
+	llist_del(&pdp->list);
+	pdp->mm = NULL;
+
+	/* stop timer 3395 */
+	pdpctx_timer_stop(pdp, 3395);
+}
+
 #if 0
 static void msgb_put_pdp_addr_ipv4(struct msgb *msg, uint32_t ipaddr)
 {
diff --git a/src/gprs/gprs_sgsn.c b/src/gprs/gprs_sgsn.c
index 55ce096..ab5e79a 100644
--- a/src/gprs/gprs_sgsn.c
+++ b/src/gprs/gprs_sgsn.c
@@ -443,9 +443,7 @@
 	osmo_signal_dispatch(SS_SGSN, S_SGSN_PDP_TERMINATE, &sig_data);
 
 	/* Detach from MM context */
-	llist_del(&pdp->list);
-	pdp->mm = NULL;
-
+	pdp_ctx_detach_mm_ctx(pdp);
 	sgsn_delete_pdp_ctx(pdp);
 }