diff --git a/nimble/host/include/host/ble_gap.h b/nimble/host/include/host/ble_gap.h
index 2a311db2a8..236a39736a 100644
--- a/nimble/host/include/host/ble_gap.h
+++ b/nimble/host/include/host/ble_gap.h
@@ -252,11 +252,14 @@ struct hci_conn_update;
 /** GAP event: Subrate change */
 #define BLE_GAP_EVENT_SUBRATE_CHANGE        28
 
+/** GAP event: Unhandled HCI event */
+#define BLE_GAP_EVENT_UNHANDLED_HCI         29
+
 /** GAP event: Vendor specific HCI event */
-#define BLE_GAP_EVENT_VS_HCI                29
+#define BLE_GAP_EVENT_VS_HCI                30
 
 /** GAP event: BIG (Broadcast Isochronous Group) information report */
-#define BLE_GAP_EVENT_BIGINFO_REPORT        30
+#define BLE_GAP_EVENT_BIGINFO_REPORT        31
 
 /** @} */
 
@@ -1288,6 +1291,18 @@ struct ble_gap_event {
         } subrate_change;
 #endif
 
+        /**
+         * Represents a received HCI event that host did not handle
+         *
+         * Valid for the following event types:
+         *     o BLE_GAP_EVENT_UNHANDLED_HCI
+         */
+        struct {
+            bool le_meta;
+            const void *ev;
+            uint8_t length;
+        } unhandled_hci;
+
 #if MYNEWT_VAL(BLE_HCI_VS)
         /**
          * Represents a received vendor-specific HCI event
diff --git a/nimble/host/src/ble_gap.c b/nimble/host/src/ble_gap.c
index 3a63050b40..7fc63a492a 100644
--- a/nimble/host/src/ble_gap.c
+++ b/nimble/host/src/ble_gap.c
@@ -6357,6 +6357,22 @@ ble_gap_mtu_event(uint16_t conn_handle, uint16_t cid, uint16_t mtu)
 #endif
 }
 
+#if MYNEWT_VAL(BLE_HS_GAP_UNHANDLED_HCI_EVENT)
+void
+ble_gap_unhandled_hci_event(bool le_meta, uint8_t len, const void *buf)
+{
+    struct ble_gap_event event;
+
+    memset(&event, 0, sizeof event);
+    event.type = BLE_GAP_EVENT_UNHANDLED_HCI;
+    event.unhandled_hci.le_meta = le_meta;
+    event.unhandled_hci.ev = buf;
+    event.unhandled_hci.length = len;
+
+    ble_gap_event_listener_call(&event);
+}
+#endif
+
 #if MYNEWT_VAL(BLE_HCI_VS)
 void
 ble_gap_vs_hci_event(const void *buf, uint8_t len)
diff --git a/nimble/host/src/ble_gap_priv.h b/nimble/host/src/ble_gap_priv.h
index 0be949da60..0ada2af6a8 100644
--- a/nimble/host/src/ble_gap_priv.h
+++ b/nimble/host/src/ble_gap_priv.h
@@ -141,6 +141,7 @@ void ble_gap_mtu_event(uint16_t conn_handle, uint16_t cid, uint16_t mtu);
 void ble_gap_identity_event(uint16_t conn_handle, const ble_addr_t *peer_id_addr);
 int ble_gap_repeat_pairing_event(const struct ble_gap_repeat_pairing *rp);
 void ble_gap_pairing_complete_event(uint16_t conn_handle, int status);
+void ble_gap_unhandled_hci_event(bool le_meta, unsigned char len, const void *buf);
 void ble_gap_vs_hci_event(const void *buf, uint8_t len);
 int ble_gap_master_in_progress(void);
 
diff --git a/nimble/host/src/ble_hs_hci_evt.c b/nimble/host/src/ble_hs_hci_evt.c
index e7af2243b8..93d92efca9 100644
--- a/nimble/host/src/ble_hs_hci_evt.c
+++ b/nimble/host/src/ble_hs_hci_evt.c
@@ -315,6 +315,10 @@ ble_hs_hci_evt_le_meta(uint8_t event_code, const void *data, unsigned int len)
     fn = ble_hs_hci_evt_le_dispatch_find(ev->subevent);
     if (fn) {
         return fn(ev->subevent, data, len);
+    } else {
+#if MYNEWT_VAL(BLE_HS_GAP_UNHANDLED_HCI_EVENT)
+        ble_gap_unhandled_hci_event(true, len, data);
+#endif
     }
 
     return 0;
@@ -910,6 +914,9 @@ ble_hs_hci_evt_process(struct ble_hci_ev *ev)
 
     entry = ble_hs_hci_evt_dispatch_find(ev->opcode);
     if (entry == NULL) {
+#if MYNEWT_VAL(BLE_HS_GAP_UNHANDLED_HCI_EVENT)
+        ble_gap_unhandled_hci_event(false, ev->length, ev->data);
+#endif
         STATS_INC(ble_hs_stats, hci_unknown_event);
         rc = BLE_HS_ENOTSUP;
     } else {
diff --git a/nimble/host/syscfg.yml b/nimble/host/syscfg.yml
index f94111c61d..8218b9e769 100644
--- a/nimble/host/syscfg.yml
+++ b/nimble/host/syscfg.yml
@@ -474,6 +474,13 @@ syscfg.defs:
             Sysinit stage for the NimBLE host.
         value: 200
 
+    BLE_HS_GAP_UNHANDLED_HCI_EVENT:
+        description: >
+            Enables GAP event for received HCI events that are not handled by
+            host. This can be used to implement/test features that are not yet
+            supported by host.
+        value: 0
+
     ### Log settings.
 
     BLE_HS_LOG_MOD: