diff --git a/android/hal-ipc-api.txt b/android/hal-ipc-api.txt
index 85a0bcf..cf6c281 100644
--- a/android/hal-ipc-api.txt
+++ b/android/hal-ipc-api.txt
@@ -1671,6 +1671,12 @@ Android HAL name: "gatt" (BT_PROFILE_GATT_ID)
 		In case of an error, the error response will be returned.
 
 	Opcode 0x18 - Unregister Server command/response
+
+		Command parameters: Server (4 octets)
+		Response parameters: <none>
+
+		In case of an error, the error response will be returned.
+
 	Opcode 0x19 - Connect Peripheral command/response
 	Opcode 0x1a - Disconnect Peripheral command/response
 	Opcode 0x1b - Add Service command/response
diff --git a/android/hal-msg.h b/android/hal-msg.h
index 750f516..2d772de 100644
--- a/android/hal-msg.h
+++ b/android/hal-msg.h
@@ -707,6 +707,11 @@ struct hal_cmd_gatt_server_register {
 	uint8_t uuid[16];
 } __attribute__((packed));
 
+#define HAL_OP_GATT_SERVER_UNREGISTER		0x18
+struct hal_cmd_gatt_server_unregister {
+	int32_t server_if;
+} __attribute__((packed));
+
 /* Notifications and confirmations */
 
 #define HAL_POWER_OFF			0x00