diff --git a/android/hal-ipc-api.txt b/android/hal-ipc-api.txt
index 7064bb7..fb7a180 100644
--- a/android/hal-ipc-api.txt
+++ b/android/hal-ipc-api.txt
@@ -1571,6 +1571,21 @@ Android HAL name: "gatt" (BT_PROFILE_GATT_ID)
 		In case of an error, the error response will be returned.
 
 	Opcode 0x0f - Write Descriptor command/response
+
+		Command parameters: Connection ID (4 octets)
+		                    Service ID (18 octets)
+		                    GATT ID (17 octets)
+		                    Descr. GATT ID (17 octets)
+		                    Write Type (4 octets)
+		                    Length (4 octets)
+		                    Authorization Req. (4 octets)
+		                    Value (variable)
+		Valid Service ID: as described in Get Included Service
+		Valid GATT ID: as described in Get Included Service
+		Response parameters: <none>
+
+		In case of an error, the error response will be returned.
+
 	Opcode 0x10 - Execute Write command/response
 	Opcode 0x11 - Register For Notification command/response
 	Opcode 0x12 - Deregister For Notification command/response
diff --git a/android/hal-msg.h b/android/hal-msg.h
index 648db18..8a37858 100644
--- a/android/hal-msg.h
+++ b/android/hal-msg.h
@@ -628,6 +628,18 @@ struct hal_cmd_gatt_client_read_descriptor {
 	int32_t auth_req;
 } __attribute__((packed));
 
+#define HAL_OP_GATT_CLIENT_WRITE_DESCRIPTOR	0x0f
+struct hal_cmd_gatt_client_write_descriptor {
+	int32_t conn_id;
+	struct hal_gatt_srvc_id srvc_id;
+	struct hal_gatt_gatt_id char_id;
+	struct hal_gatt_gatt_id descr_id;
+	int32_t write_type;
+	int32_t len;
+	int32_t auth_req;
+	uint8_t value[0];
+} __attribute__((packed));
+
 /* Notifications and confirmations */
 
 #define HAL_POWER_OFF			0x00