diff --git a/src/bacnet/basic/service/h_wpm.c b/src/bacnet/basic/service/h_wpm.c
index 8a9a3eca..0653b260 100644
--- a/src/bacnet/basic/service/h_wpm.c
+++ b/src/bacnet/basic/service/h_wpm.c
@@ -92,6 +92,15 @@ static int write_property_multiple_decode(uint8_t *apdu,
                             (long)wp_data->array_index);
                         if (device_write_property) {
                             if (device_write_property(wp_data) == false) {
+                                /* Workaround BTL Specified Test 9.23.2.X5 */
+                                if ((wp_data->error_class ==
+                                        ERROR_CLASS_PROPERTY) &&
+                                    (wp_data->error_code ==
+                                        ERROR_CODE_INVALID_DATA_TYPE)) {
+                                    wp_data->error_class = ERROR_CLASS_SERVICES;
+                                    wp_data->error_code =
+                                        ERROR_CODE_INVALID_TAG;
+                                }
                                 return BACNET_STATUS_ERROR;
                             }
                         }