diff --git a/src/onc/modules/_OncService.py b/src/onc/modules/_OncService.py
index d278b02..a1d3c78 100644
--- a/src/onc/modules/_OncService.py
+++ b/src/onc/modules/_OncService.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import logging
+import pprint
 import weakref
 from time import time
 from urllib import parse
@@ -8,6 +10,8 @@
 
 from ._util import _createErrorMessage, _formatDuration
 
+logging.basicConfig(format="%(levelname)s: %(message)s")
+
 
 class _OncService:
     """
@@ -60,6 +64,26 @@ def _doRequest(self, url: str, filters: dict | None = None, getTime: bool = Fals
                 response.raise_for_status()
         self._log(f"Web Service response time: {_formatDuration(responseTime)}")
 
+        # Log warning messages only when showWarning is True
+        # and jsonResult["messages"] is not an empty list
+        if (
+            self._config("showWarning")
+            and "messages" in jsonResult
+            and jsonResult["messages"]
+        ):
+            long_message = "\n".join(
+                [f"* {message}" for message in jsonResult["messages"]]
+            )
+
+            filters_without_token = filters.copy()
+            del filters_without_token["token"]
+            filters_str = pprint.pformat(filters_without_token)
+
+            logging.warning(
+                f"When calling {url} with filters\n{filters_str},\n"
+                f"there are several warning messages:\n{long_message}\n"
+            )
+
         if getTime:
             return jsonResult, responseTime
         else:
diff --git a/src/onc/onc.py b/src/onc/onc.py
index bcf1a8e..c0569df 100644
--- a/src/onc/onc.py
+++ b/src/onc/onc.py
@@ -32,6 +32,9 @@ class ONC:
 
         - True: Print all information and debug messages (intended for debugging).
         - False: Only print information messages.
+    showWarning : boolean, default True
+        Whether warning messages are displayed. Some web services have "messages" key in the response JSON
+        to indicate that something might need attention, like using a default value for a missing parameter.
     outPath : str | Path, default "output"
         The directory that files are saved to (relative to the current directory) when downloading files.
         The directory will be created if it does not exist during the download.
@@ -50,11 +53,13 @@ def __init__(
         token,
         production: bool = True,
         showInfo: bool = False,
+        showWarning: bool = True,
         outPath: str | Path = "output",
         timeout: int = 60,
     ):
         self.token = re.sub(r"[^a-zA-Z0-9\-]+", "", token)
         self.showInfo = showInfo
+        self.showWarning = showWarning
         self.timeout = timeout
         self.production = production
         self.outPath = outPath