diff --git a/src/ble/att_server.c b/src/ble/att_server.c
index 652df474b..099409f3b 100644
--- a/src/ble/att_server.c
+++ b/src/ble/att_server.c
@@ -60,7 +60,6 @@
 #include "btstack_memory.h"
 #include "btstack_run_loop.h"
 #include "gap.h"
-#include "hci.h"
 #include "hci_dump.h"
 #include "l2cap.h"
 #include "btstack_tlv.h"
@@ -118,13 +117,6 @@ static hci_con_handle_t att_server_last_can_send_now = HCI_CON_HANDLE_INVALID;
 static uint8_t att_server_flags;
 
 #ifdef ENABLE_GATT_OVER_EATT
-typedef struct {
-    btstack_linked_item_t item;
-    att_server_t     att_server;
-    att_connection_t att_connection;
-    uint8_t * receive_buffer;
-    uint8_t * send_buffer;
-} att_server_eatt_bearer_t;
 static att_server_eatt_bearer_t * att_server_eatt_bearer_for_con_handle(hci_con_handle_t con_handle);
 static btstack_linked_list_t att_server_eatt_bearer_pool;
 static btstack_linked_list_t att_server_eatt_bearer_active;
@@ -1684,8 +1676,6 @@ uint8_t att_server_eatt_init(uint8_t num_eatt_bearers, uint8_t * storage_buffer,
         eatt_bearer++;
     }
     // TODO: define minimum EATT MTU
-    l2cap_ecbm_register_service(att_server_eatt_handler, BLUETOOTH_PSM_EATT, 64, LEVEL_2, false);
-
-    return 0;
+    return l2cap_ecbm_register_service(att_server_eatt_handler, BLUETOOTH_PSM_EATT, 64, LEVEL_2, false);
 }
 #endif
diff --git a/src/ble/att_server.h b/src/ble/att_server.h
index 71566b827..fa46fe502 100644
--- a/src/ble/att_server.h
+++ b/src/ble/att_server.h
@@ -44,6 +44,7 @@
 #define ATT_SERVER_H
 
 #include <stdint.h>
+#include "hci.h"
 #include "ble/att_db.h"
 #include "btstack_defines.h"
 #include "btstack_config.h"
@@ -52,6 +53,16 @@
 extern "C" {
 #endif
 
+#ifdef ENABLE_GATT_OVER_EATT
+typedef struct {
+    btstack_linked_item_t item;
+    att_server_t     att_server;
+    att_connection_t att_connection;
+    uint8_t * receive_buffer;
+    uint8_t * send_buffer;
+} att_server_eatt_bearer_t;
+#endif
+
 /* API_START */
 /*
  * @brief setup ATT server
@@ -66,8 +77,10 @@ void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_
  * @note Requires ENABLE_GATT_OVER_EATT
  * @param num_eatt_bearers
  * @param storage_buffer
- * @param storage_size
- * @return
+ * @param storage_size must be >= num_eatt_bearers * sizeof(att_server_eatt_bearer_t)
+ * @return status   ERROR_CODE_SUCCESS
+ *                  ERROR_CODE_MEMORY_CAPACITY_EXCEEDED if buffer too small or no entry in l2cap service pool
+ *                  L2CAP_SERVICE_ALREADY_REGISTERED if called twice
  */
 uint8_t att_server_eatt_init(uint8_t num_eatt_bearers, uint8_t * storage_buffer, uint16_t storage_size);