diff --git a/client/gatt.c b/client/gatt.c
index 9d35b54..e5bab6d 100644
--- a/client/gatt.c
+++ b/client/gatt.c
@@ -2144,6 +2144,12 @@ static void authorize_write_response(const char *input, void *user_data)
 		goto error;
 	}
 
+	if (aad->offset > chrc->value_len) {
+		err = "org.bluez.Error.InvalidOffset";
+
+		goto error;
+	}
+
 	/* Authorization check of prepare writes */
 	if (prep_authorize) {
 		reply = g_dbus_create_reply(pending_message, DBUS_TYPE_INVALID);
@@ -2275,6 +2281,11 @@ static DBusMessage *chrc_write_value(DBusConnection *conn, DBusMessage *msg,
 		return NULL;
 	}
 
+	if (offset > chrc->value_len)
+		return g_dbus_create_error(msg,
+				"org.bluez.Error.InvalidOffset", NULL);
+
+
 	/* Authorization check of prepare writes */
 	if (prep_authorize)
 		return g_dbus_create_reply(msg, DBUS_TYPE_INVALID);
@@ -2686,6 +2697,10 @@ static DBusMessage *desc_write_value(DBusConnection *conn, DBusMessage *msg,
 		return g_dbus_create_error(msg,
 				"org.bluez.Error.InvalidArguments", NULL);
 
+	if (offset > desc->value_len)
+		return g_dbus_create_error(msg,
+				"org.bluez.Error.InvalidOffset", NULL);
+
 	if (write_value(&desc->value_len, &desc->value, value,
 					value_len, offset, desc->max_val_len))
 		return g_dbus_create_error(msg,