diff --git a/src/gap.h b/src/gap.h
index d5d618e56..37b60512e 100644
--- a/src/gap.h
+++ b/src/gap.h
@@ -320,6 +320,7 @@ typedef struct {
     hci_con_handle_t acl_con_handles[MAX_NR_CIS];
     bool cis_setup_active[MAX_NR_CIS];
     bool cis_established[MAX_NR_CIS];
+    uint8_t highest_outgoing_cis_index;
     // request to send
     bool can_send_now_requested;
 } le_audio_cig_t;
diff --git a/src/hci.c b/src/hci.c
index 6b8f611c6..fc257aab4 100644
--- a/src/hci.c
+++ b/src/hci.c
@@ -10855,8 +10855,9 @@ uint8_t gap_cis_create(uint8_t cig_id, hci_con_handle_t cis_con_handles [], hci_
         return ERROR_CODE_COMMAND_DISALLOWED;
     }
 
-    // store ACL Connection Handles
+    // store ACL Connection Handles and set highest outgoing cis index
     uint8_t i;
+    cig->highest_outgoing_cis_index = 0;
     for (i=0;i<cig->num_cis;i++){
         // check that all con handles exist and store
         hci_con_handle_t cis_handle = cis_con_handles[i];
@@ -10872,6 +10873,9 @@ uint8_t gap_cis_create(uint8_t cig_id, hci_con_handle_t cis_con_handles [], hci_
                 btstack_assert(iso_stream != NULL);
                 iso_stream->acl_handle = acl_con_handles[j];
                 found = true;
+                if (iso_stream->max_sdu_c_to_p > 0) {
+                    cig->highest_outgoing_cis_index = i;
+                }
                 break;
             }
         }