diff --git a/nimble/host/audio/services/bass/include/services/bass/ble_audio_svc_bass.h b/nimble/host/audio/services/bass/include/services/bass/ble_audio_svc_bass.h
index 431ecb968..41f79b7bc 100644
--- a/nimble/host/audio/services/bass/include/services/bass/ble_audio_svc_bass.h
+++ b/nimble/host/audio/services/bass/include/services/bass/ble_audio_svc_bass.h
@@ -324,8 +324,9 @@ struct ble_svc_audio_bass_operation {
             /** Number of subgroups */
             uint16_t num_subgroups;
 
-            /** BIS Synchronisation of subgroups */
-            uint32_t bis_sync[BLE_SVC_AUDIO_BASS_SUB_NUM_MAX];
+            /** Subgroup entries */
+            struct ble_svc_audio_bass_subgroup
+                subgroups[BLE_SVC_AUDIO_BASS_SUB_NUM_MAX];
         } modify_source;
 
         /**
diff --git a/nimble/host/audio/services/bass/src/ble_audio_svc_bass.c b/nimble/host/audio/services/bass/src/ble_audio_svc_bass.c
index 451b766dd..fb8634a62 100644
--- a/nimble/host/audio/services/bass/src/ble_audio_svc_bass.c
+++ b/nimble/host/audio/services/bass/src/ble_audio_svc_bass.c
@@ -424,20 +424,20 @@ ble_svc_audio_bass_add_source(uint8_t *data, uint16_t data_len, uint16_t conn_ha
 }
 
 static int
-check_bis_sync(uint16_t num_subgroups, const uint32_t *bis_sync_list)
+check_bis_sync(uint16_t num_subgroups, struct ble_svc_audio_bass_subgroup subgroups)
 {
     uint32_t bis_sync_mask = 0;
     int i;
     int j;
 
     for (i = 0; i < num_subgroups; i++) {
-        if (bis_sync_list[i] != 0xFFFFFFFF) {
+        if (subgroups[i].bis_sync != 0xFFFFFFFF) {
             for (j = 0; j < num_subgroups; j++) {
-                if (bis_sync_list[i] & bis_sync_mask) {
+                if (subgroups[i].bis_sync & bis_sync_mask) {
                     return BLE_HS_EINVAL;
                 }
 
-                bis_sync_mask |= bis_sync_list[i];
+                bis_sync_mask |= subgroups[i].bis_sync;
             }
         }
     }
@@ -496,12 +496,12 @@ ble_svc_audio_bass_modify_source(uint8_t *data, uint16_t data_len, uint16_t conn
     }
 
     for (i = 0; i < operation.modify_source.num_subgroups; i++) {
-        operation.modify_source.bis_sync[i] = get_le32(&data[offset]);
+        operation.modify_source.subgroups.bis_sync[i] = get_le32(&data[offset]);
         offset += 4;
     }
 
     if (check_bis_sync(operation.modify_source.num_subgroups,
-                       operation.modify_source.bis_sync)) {
+                       operation.modify_source.subgroups)) {
         rc = BLE_HS_EINVAL;
         ev.bass_operation_status.status = BLE_HS_EREJECT;
         goto done;
diff --git a/nimble/host/audio/src/ble_audio_scan_delegator.c b/nimble/host/audio/src/ble_audio_scan_delegator.c
index 60e04adc3..08a5ac645 100644
--- a/nimble/host/audio/src/ble_audio_scan_delegator.c
+++ b/nimble/host/audio/src/ble_audio_scan_delegator.c
@@ -197,8 +197,9 @@ bass_modify_source_op_handler(struct ble_svc_audio_bass_operation *op, void *arg
     BLE_AUDIO_DBG_ASSERT(sync_opt->num_subgroups < ARRAY_SIZE(sync_opt->subgroups));
 
     for (uint8_t i = 0; i < sync_opt->num_subgroups; i++) {
-        sync_opt->subgroups[i].bis_sync = op->modify_source.bis_sync[i];
-        /* FIXME: Missing metadata in Modify Source */
+        sync_opt->subgroups[i].bis_sync = op->modify_source.subgroups[i].bis_sync_state;
+        sync_opt->subgroups[i].metadata_length = op->modify_source.subgroups[i].metadata_length;
+        sync_opt->subgroups[i].metadata = op->modify_source.subgroups[i].metadata;
     }
 
     action.type = BLE_AUDIO_SCAN_DELEGATOR_ACTION_SOURCE_MODIFY;