diff --git a/google/resource_big_query_job.go b/google/resource_big_query_job.go
index b46b4eb8344..5fb71151cce 100644
--- a/google/resource_big_query_job.go
+++ b/google/resource_big_query_job.go
@@ -1864,7 +1864,7 @@ func expandBigQueryJobConfigurationQuery(v interface{}, d TerraformResourceData,
 	transformedUseLegacySql, err := expandBigQueryJobConfigurationQueryUseLegacySql(original["use_legacy_sql"], d, config)
 	if err != nil {
 		return nil, err
-	} else if val := reflect.ValueOf(transformedUseLegacySql); val.IsValid() && !isEmptyValue(val) {
+	} else if val := reflect.ValueOf(transformedUseLegacySql); val.IsValid() {
 		transformed["useLegacySql"] = transformedUseLegacySql
 	}
 
diff --git a/website/docs/r/bigquery_job.html.markdown b/website/docs/r/bigquery_job.html.markdown
index c13a7dcf274..f6b3cd5b62d 100644
--- a/website/docs/r/bigquery_job.html.markdown
+++ b/website/docs/r/bigquery_job.html.markdown
@@ -381,6 +381,8 @@ The `query` block supports:
 * `query` -
   (Required)
   SQL query text to execute. The useLegacySql field can be used to indicate whether the query uses legacy SQL or standard SQL.
+  *NOTE*: queries containing [DML language](https://cloud.google.com/bigquery/docs/reference/standard-sql/data-manipulation-language) 
+  (`DELETE`, `UPDATE`, `MERGE`, `INSERT`) must specify `create_disposition = ""` and `write_disposition = ""`.
 
 * `destination_table` -
   (Optional)