diff --git a/doc/progress.rst b/doc/progress.rst
index 286666767..00da01042 100644
--- a/doc/progress.rst
+++ b/doc/progress.rst
@@ -8,6 +8,7 @@ Changelog
 
 0.13.0
 ~~~~~~
+ * MAINT#1143: Change default argument for ``avoid_duplicate_runs`` of ``run_model_on_task`` to false to avoid requiring an API key by default.
  * FIX#1030: ``pre-commit`` hooks now no longer should issue a warning.
  * FIX#1110: Make arguments to ``create_study`` and ``create_suite`` that are defined as optional by the OpenML XSD actually optional.
  * MAIN#1088: Do CI for Windows on Github Actions instead of Appveyor.
diff --git a/openml/runs/functions.py b/openml/runs/functions.py
index 8bbe3b956..e2a0fb732 100644
--- a/openml/runs/functions.py
+++ b/openml/runs/functions.py
@@ -48,7 +48,7 @@
 def run_model_on_task(
     model: Any,
     task: Union[int, str, OpenMLTask],
-    avoid_duplicate_runs: bool = True,
+    avoid_duplicate_runs: bool = False,
     flow_tags: List[str] = None,
     seed: int = None,
     add_local_measures: bool = True,
@@ -68,7 +68,7 @@ def run_model_on_task(
     task : OpenMLTask or int or str
         Task to perform or Task id.
         This may be a model instead if the first argument is an OpenMLTask.
-    avoid_duplicate_runs : bool, optional (default=True)
+    avoid_duplicate_runs : bool, optional (default=False)
         If True, the run will throw an error if the setup/task combination is already present on
         the server. This feature requires an internet connection.
     flow_tags : List[str], optional (default=None)