diff --git a/android/hal-ipc-api.txt b/android/hal-ipc-api.txt
index 08dbed6..9aee3ab 100644
--- a/android/hal-ipc-api.txt
+++ b/android/hal-ipc-api.txt
@@ -2026,5 +2026,16 @@ Android HAL name: "gatt" (BT_PROFILE_GATT_ID)
 		                         Is Long (1 octet)
 
 	Opcode 0x9d - Request Write notification
+
+		Notification parameters: Connection ID (4 octets)
+		                         Trans ID (4 octets)
+		                         Address (6 octets)
+		                         Attribute Handle (4 octets)
+		                         Offset (4 octets)
+		                         Length (4 octets)
+		                         Need Response (4 octets)
+		                         Is Prepare (1 octet)
+		                         Value (variable)
+
 	Opcode 0x9e - Request Execute Write notification
 	Opcode 0x9f - Response Confirmation notification
diff --git a/android/hal-msg.h b/android/hal-msg.h
index 4c70d90..d865448 100644
--- a/android/hal-msg.h
+++ b/android/hal-msg.h
@@ -1466,3 +1466,16 @@ struct hal_ev_gatt_server_request_read {
 	int32_t offset;
 	uint8_t is_long;
 } __attribute__((packed));
+
+#define HAL_EV_GATT_SERVER_REQUEST_WRITE	0x9d
+struct hal_ev_gatt_server_request_write {
+	int32_t conn_id;
+	int32_t trans_id;
+	uint8_t bdaddr[6];
+	int32_t attr_handle;
+	int32_t offset;
+	int32_t length;
+	uint8_t need_rsp;
+	uint8_t is_prep;
+	uint8_t value[0];
+} __attribute__((packed));