diff --git a/ble/att_server.c b/ble/att_server.c
index b30bea1a7..ae4b89c28 100644
--- a/ble/att_server.c
+++ b/ble/att_server.c
@@ -87,6 +87,9 @@ static timer_source_t att_handle_value_indication_timer;
 static btstack_packet_handler_t att_client_packet_handler = NULL;
 
 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){
+    
+    if (!att_client_packet_handler) return;
+    
     uint8_t event[7];
     int pos = 0;
     event[pos++] = ATT_HANDLE_VALUE_INDICATION_COMPLETE;