diff --git a/src/data/bigquery_builder.rs b/src/data/bigquery_builder.rs
index 54840f4..6d400da 100644
--- a/src/data/bigquery_builder.rs
+++ b/src/data/bigquery_builder.rs
@@ -76,14 +76,14 @@ impl<'a, Table> BigQueryBuilder<'a, Table>
         }
 
         let query_res = query_res.rows.unwrap();
-        println!("query_res: {:?}", query_res);
+        log::debug!("query_res: {:?}", query_res);
         let mut result: Vec<Table> = Vec::new();
         for row in query_res {
             let row = row.f.unwrap();
             let mut row_data: HashMap<String, Value> = HashMap::new();
             for (i, field) in row.into_iter().enumerate() {
                 let field = field.v.unwrap_or(Value::Null);
-                println!("{}: {}", fields[i], field);
+                log::debug!("{}: {}", fields[i], field);
                 row_data.insert(fields[i].clone(), field);
             }
             let data = Table::new_from_query_result_row(client, &row_data)?;
@@ -98,7 +98,6 @@ impl<'a, Table> BigQueryBuilder<'a, Table>
             query: Some(self.build_query_string()),
             query_parameters: Some(self.required_params),
             use_legacy_sql: Some(false),
-            /*TODO: is this line needed?: use_legacy_sql: Some(false),*/
             ..Default::default()
         }
     }
@@ -202,7 +201,7 @@ impl<'a, Table> BigQueryBuilder<'a, Table>
                     .collect()
             }
         };
-        println!("fields: {:?}", fields);
+        log::debug!("fields: {:?}", fields);
         fields.sort();
         fields
     }
diff --git a/tests/tests.rs b/tests/tests.rs
index 6d3fc1b..51abb8f 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -22,17 +22,17 @@ pub struct DbInfos<'a> {
 
 #[tokio::test]
 async fn test_get_table_name() {
-    init_logger(LevelFilter::Debug);
+    init_logger();
     let pk = DbInfos::get_table_name();
-    println!("table name: {}", pk);
+    log::debug!("table name: {}", pk);
     assert_eq!("Infos", pk, "table name is not correct")
 }
 
 #[tokio::test]
 async fn test_get_query_fields() {
-    init_logger(LevelFilter::Debug);
+    init_logger();
     let fields = DbInfos::get_query_fields(true);
-    println!("fields: {:?}", fields);
+    log::debug!("fields: {:?}", fields);
     assert_eq!(6, fields.len(), "fields length is not correct");
     assert_eq!("Id", fields.get("row_id").unwrap(), );
     assert_eq!("info1", fields.get("info1").unwrap(), );
@@ -44,7 +44,7 @@ async fn test_get_query_fields() {
 
 #[tokio::test]
 async fn test_query_builder_1() {
-    init_logger(LevelFilter::Debug);
+    init_logger();
     let client = get_test_client().await;
     let query_builder: BigQueryBuilder<DbInfos> = DbInfos::query(&client);
     let query_builder: BigQueryBuilder<DbInfos> = query_builder
@@ -60,9 +60,9 @@ async fn test_query_builder_1() {
     WHERE info1 is NULL AND info3 = @__PARAM_0 \
     ORDER BY info ASC LIMIT 1000",
     );
-    println!("query   : {}", query_string);
-    println!("expected: {}", expected_query_string);
-    println!("request: {:?}", query_builder.clone().build_query_request());
+    log::debug!("query   : {}", query_string);
+    log::debug!("expected: {}", expected_query_string);
+    log::debug!("request: {:?}", query_builder.clone().build_query_request());
 
     assert_eq!(query_string, expected_query_string);
     assert_eq!(
@@ -75,7 +75,7 @@ async fn test_query_builder_1() {
         1
     );
     let res = query_builder.clone().run().await.unwrap();
-    println!("res: {:?}", res);
+    log::debug!("res: {:?}", res);
 }
 
 async fn get_test_client() -> BigqueryClient {
@@ -86,7 +86,7 @@ async fn get_test_client() -> BigqueryClient {
 
 #[tokio::test]
 async fn simple_query() {
-    init_logger(LevelFilter::Info);
+    init_logger();
     let client = get_test_client().await;
     let q = DbInfos::query(&client)
         .add_order_by(name_of!(row_id in DbInfos), OrderDirection::Descending)
@@ -100,9 +100,12 @@ async fn simple_query() {
     }
 }
 
-fn init_logger(level: LevelFilter) {
+fn init_logger() {
     let _ = env_logger::builder()
         .is_test(true)
-        .filter_level(level)
+        .filter_level(LevelFilter::Info)
+        .filter_module("google_bigquery_v2", LevelFilter::Trace)
+        .filter_module("google_bigquery_v2_derive", LevelFilter::Trace)
+        .filter_module("tests", LevelFilter::Trace)
         .try_init();
 }