diff --git a/trino/logging.py b/trino/logging.py
index 866c3e92..64c64ab2 100644
--- a/trino/logging.py
+++ b/trino/logging.py
@@ -11,12 +11,20 @@
 # limitations under the License.
 
 import logging
+from typing import Optional
 
 LEVEL = logging.INFO
 
 
 # TODO: provide interface to use ``logging.dictConfig``
-def get_logger(name: str, log_level: int = LEVEL) -> logging.Logger:
+def get_logger(name: str, log_level: Optional[int]) -> logging.Logger:
     logger = logging.getLogger(name)
-    logger.setLevel(log_level)
+    # We must not call setLevel by default except on the root logger otherwise
+    # we cannot change log levels for all modules by changing level of the root
+    # logger
+    if log_level is not None:
+        logger.setLevel(log_level)
     return logger
+
+# set default log level to LEVEL
+trino_root_logger = get_logger('trino', LEVEL)