diff --git a/src/host/layer23/include/osmocom/bb/mobile/primitives.h b/src/host/layer23/include/osmocom/bb/mobile/primitives.h
index 6804fc0ef..39b494540 100644
--- a/src/host/layer23/include/osmocom/bb/mobile/primitives.h
+++ b/src/host/layer23/include/osmocom/bb/mobile/primitives.h
@@ -19,6 +19,7 @@ enum mobile_prims {
 	PRIM_MOB_STARTED,
 	PRIM_MOB_SHUTDOWN,
 	PRIM_MOB_SMS,
+	PRIM_MOB_MM,
 };
 
 struct mobile_prim_intf {
@@ -65,6 +66,15 @@ struct mobile_sms_param {
 	int cause;
 };
 
+/**
+ * Mobility Management (MM) state changes.
+ */
+struct mobile_mm_param {
+	int state;			/*!< The new MM state */
+	int substate;			/*!< The current substate */
+	int prev_substate;		/*!< The previous substate */
+};
+
 struct mobile_prim {
 	struct osmo_prim_hdr hdr;	/*!< Primitive base class */
 	union {
@@ -72,6 +82,7 @@ struct mobile_prim {
 		struct mobile_started_param started;
 		struct mobile_shutdown_param shutdown;
 		struct mobile_sms_param sms;
+		struct mobile_mm_param mm;
 	} u;
 };
 
@@ -86,3 +97,4 @@ void mobile_prim_ntfy_started(struct osmocom_ms *ms, bool started);
 void mobile_prim_ntfy_shutdown(struct osmocom_ms *ms, int old_state, int new_state);
 void mobile_prim_ntfy_sms_new(struct osmocom_ms *ms, struct gsm_sms *sms);
 void mobile_prim_ntfy_sms_status(struct osmocom_ms *ms, struct gsm_sms *sms, uint8_t cause);
+void mobile_prim_ntfy_mm_status(struct osmocom_ms *ms, int state, int subs, int old_subs);
diff --git a/src/host/layer23/src/mobile/gsm48_mm.c b/src/host/layer23/src/mobile/gsm48_mm.c
index f32d57ab4..a7af1f5cf 100644
--- a/src/host/layer23/src/mobile/gsm48_mm.c
+++ b/src/host/layer23/src/mobile/gsm48_mm.c
@@ -39,6 +39,7 @@
 #include <osmocom/bb/mobile/gsm480_ss.h>
 #include <osmocom/bb/mobile/gsm411_sms.h>
 #include <osmocom/bb/mobile/app_mobile.h>
+#include <osmocom/bb/mobile/primitives.h>
 #include <osmocom/bb/mobile/vty.h>
 
 extern void *l23_ctx;
@@ -961,6 +962,7 @@ static void new_mm_state(struct gsm48_mmlayer *mm, int state, int substate)
 
 	mm->state = state;
 	mm->substate = substate;
+	mobile_prim_ntfy_mm_status(ms, mm->state, mm->substate, mm->mr_substate);
 
 	/* resend detach event, if flag is set */
 	if (state == GSM48_MM_ST_MM_IDLE && mm->delay_detach) {
diff --git a/src/host/layer23/src/mobile/primitives.c b/src/host/layer23/src/mobile/primitives.c
index 0902139e0..fd486ea22 100644
--- a/src/host/layer23/src/mobile/primitives.c
+++ b/src/host/layer23/src/mobile/primitives.c
@@ -144,6 +144,16 @@ void mobile_prim_ntfy_sms_status(struct osmocom_ms *ms, struct gsm_sms *sms, uin
 	dispatch(ms, prim);
 }
 
+void mobile_prim_ntfy_mm_status(struct osmocom_ms *ms, int state, int substate, int mr_substate)
+{
+	struct mobile_prim *prim = mobile_prim_alloc(PRIM_MOB_MM, PRIM_OP_INDICATION);
+
+	prim->u.mm.state = state;
+	prim->u.mm.substate = substate;
+	prim->u.mm.prev_substate = mr_substate;
+	dispatch(ms, prim);
+}
+
 static int cancel_timer(struct mobile_prim_intf *intf, struct mobile_timer_param *param)
 {
 	struct timer_closure *closure;