diff --git a/pyproject.toml b/pyproject.toml
index 129fd2f2..867a6eef 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,7 +16,7 @@ classifiers = [
 ]
 requires-python = ">=3.8"
 dependencies = [
-    "ewokscore >=5",
+    "ewokscore >=5.1.0rc5",
     "orange-canvas-core>=0.1.35",
     "orange-widget-base>=4.22.0",
     "importlib-resources; python_version<'3.9'",
diff --git a/src/ewoksorange/gui/concurrency/_controllers/_in_process.py b/src/ewoksorange/gui/concurrency/_controllers/_in_process.py
index 6d78e289..cb72dc53 100644
--- a/src/ewoksorange/gui/concurrency/_controllers/_in_process.py
+++ b/src/ewoksorange/gui/concurrency/_controllers/_in_process.py
@@ -32,4 +32,4 @@ def aborted(self) -> bool:
         with self._lock:
             task = self._task
 
-        return task is not None and task.cancelled
+        return task is not None and task.stop_requested
diff --git a/src/ewoksorange/gui/concurrency/_runners/abstract.py b/src/ewoksorange/gui/concurrency/_runners/abstract.py
index cfca1371..0abb39d5 100644
--- a/src/ewoksorange/gui/concurrency/_runners/abstract.py
+++ b/src/ewoksorange/gui/concurrency/_runners/abstract.py
@@ -52,24 +52,20 @@ def _create_task(self) -> Task:
         return self._task_class(**self._task_kwargs)
 
     def _execute(self, task: Task) -> VariableContainer:
-        """Execute `task`, cancelling it for as long as `abort_event` is set."""
+        """Execute `task`, aborting it for as long as `abort_event` is set."""
         done = threading.Event()
 
         def _watch_abort():
             """
-            Currently `task.cancel()` and `task.cancelled` are ill-defined.
-
-            The flag `task.cancelled` could be the request or the state.
-
-            `task.execute()` resets the task's `cancelled` flag, which
-            can silently undo a `cancel()` racing with the start
+            `task.execute()` resets the task's `stop_requested` flag, which
+            can silently undo a `request_stop()` racing with the start
             of execution.
 
-            For this reason this watcher thread keeps re-applying `task.cancel()`
+            For this reason this watcher thread keeps re-applying `task.request_stop()`
             until execution finishes, so a task's `run()` reliably observes it
             regardless of the timing.
 
-            The output of a cancelled task is undefined. It could be an
+            The output of an aborted task is undefined. It could be an
             exception, undefined outputs, pertially defined outputs or
             fully defined outputs.
             """
@@ -80,7 +76,7 @@ def _watch_abort():
                     # finished without ever being aborted.
                     return
                 while not done.is_set():
-                    task.cancel()
+                    task.request_stop()
                     done.wait(timeout=0.01)
             except self._TRANSIENT_ABORT_ERRORS:
                 pass
diff --git a/src/ewoksorange/gui/concurrency/_runners/process.py b/src/ewoksorange/gui/concurrency/_runners/process.py
index b97e50f5..1cadd465 100644
--- a/src/ewoksorange/gui/concurrency/_runners/process.py
+++ b/src/ewoksorange/gui/concurrency/_runners/process.py
@@ -37,7 +37,7 @@ def _announce_started(self, task: Task) -> None:
 
     def _finalize(self, task: Task) -> None:
         try:
-            if task.cancelled:
+            if task.stop_requested:
                 self._aborted_event.set()
         except self._TRANSIENT_ABORT_ERRORS:
             pass
diff --git a/src/ewoksorange/gui/concurrency/threaded.py b/src/ewoksorange/gui/concurrency/threaded.py
index 5efa9105..d55b2ca4 100644
--- a/src/ewoksorange/gui/concurrency/threaded.py
+++ b/src/ewoksorange/gui/concurrency/threaded.py
@@ -28,7 +28,7 @@ def stop(self, timeout: Optional[float] = None, wait: bool = False) -> None:
     def cancel_running_task(self):
         """
         cancel current processing.
-        The targetted EwoksTask must have implemented the 'cancel' function
+        The targetted EwoksTask must have implemented the '_on_stop_requested' function
         """
         if self.current_task is not None:
-            self.current_task.cancel()
+            self.current_task.request_stop()
diff --git a/src/ewoksorange/tests/executor/tasks.py b/src/ewoksorange/tests/executor/tasks.py
index 7b89c943..254404f1 100644
--- a/src/ewoksorange/tests/executor/tasks.py
+++ b/src/ewoksorange/tests/executor/tasks.py
@@ -1,4 +1,5 @@
 import os
+import threading
 import time
 
 from ewokscore import TaskWithProgress
@@ -24,7 +25,7 @@ def run(self):
             period = self.inputs.delay / 40
             for i in range(40):
                 time.sleep(period)
-                if self.cancelled:
+                if self.stop_requested:
                     raise CustomCancelled(f"cancelled after {(i + 1) * period} seconds")
 
         if self.inputs.fail:
@@ -37,9 +38,9 @@ def run(self):
 
         self.outputs.result = result
 
-    def cancel(self):
-        """Interpretation #2: self.cancelled is the request not the state."""
-        self.cancelled = True
+    def _on_stop_requested(self):
+        """Nothing to do: `run()` polls `self.stop_requested`."""
+        pass
 
 
 class RequestCancelTask(
@@ -53,15 +54,15 @@ def run(self):
         step = 0.05
         elapsed = 0.0
         while elapsed < self.inputs.duration:
-            if self.cancelled:
+            if self.stop_requested:
                 return
             time.sleep(step)
             elapsed += step
         self.outputs.result = f"slept {elapsed:.2f}s"
 
-    def cancel(self):
-        """Interpretation #2: self.cancelled is the request not the state."""
-        self.cancelled = True
+    def _on_stop_requested(self):
+        """Nothing to do: `run()` polls `self.stop_requested`."""
+        pass
 
 
 class PartialCancelTask(
@@ -77,16 +78,16 @@ def run(self):
         step = 0.05
         elapsed = 0.0
         while elapsed < self.inputs.duration:
-            if self.cancelled:
+            if self.stop_requested:
                 return
             time.sleep(step)
             elapsed += step
 
         self.outputs.second = "second done"
 
-    def cancel(self):
-        """Interpretation #2: self.cancelled is the request not the state."""
-        self.cancelled = True
+    def _on_stop_requested(self):
+        """Nothing to do: `run()` polls `self.stop_requested`."""
+        pass
 
 
 class IgnoreCancelTask(
@@ -94,43 +95,36 @@ class IgnoreCancelTask(
     input_names=["duration"],
     output_names=["result"],
 ):
-    """Never checks `self.cancelled`; always completes fully despite cancel()."""
+    """Never checks `self.stop_requested`; always completes fully despite request_stop()."""
 
     def run(self):
         time.sleep(self.inputs.duration)
         self.outputs.result = "completed despite abort"
 
-    def cancel(self):
-        """Interpretation #2: self.cancelled is the request not the state."""
-        self.cancelled = True
+    def _on_stop_requested(self):
+        """Nothing to do: `run()` polls `self.stop_requested`."""
+        pass
 
 
-class StateCancelTask(
+class InterruptCancelTask(
     Task,
     input_names=["duration"],
     output_names=["result"],
 ):
-    """cancel() only records a request; run() itself sets `self.cancelled`
-    once stopped."""
+    """Never polls `self.stop_requested`; `_on_stop_requested()` interrupts
+    the blocking wait of run() instead."""
 
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
-        self.__cancel_requested = False
+        self.__stop_event = threading.Event()
 
     def run(self):
-        step = 0.05
-        elapsed = 0.0
-        while elapsed < self.inputs.duration:
-            if self.__cancel_requested:
-                self.cancelled = True
-                return
-            time.sleep(step)
-            elapsed += step
-        self.outputs.result = f"slept {elapsed:.2f}s"
+        if self.__stop_event.wait(timeout=self.inputs.duration):
+            return
+        self.outputs.result = f"slept {self.inputs.duration:.2f}s"
 
-    def cancel(self):
-        """Interpretation #1: self.cancelled is the state not the request."""
-        self.__cancel_requested = True
+    def _on_stop_requested(self):
+        self.__stop_event.set()
 
 
 class TimedTask(
diff --git a/src/ewoksorange/tests/executor/test_executor_abort.py b/src/ewoksorange/tests/executor/test_executor_abort.py
index 32ca8d78..b89dae4d 100644
--- a/src/ewoksorange/tests/executor/test_executor_abort.py
+++ b/src/ewoksorange/tests/executor/test_executor_abort.py
@@ -5,9 +5,9 @@
 
 from .tasks import AddTask
 from .tasks import IgnoreCancelTask
+from .tasks import InterruptCancelTask
 from .tasks import PartialCancelTask
 from .tasks import RequestCancelTask
-from .tasks import StateCancelTask
 
 
 def test_abort(ewoksorange_qtapp, executor_context_factory):
@@ -42,14 +42,14 @@ def test_abort(ewoksorange_qtapp, executor_context_factory):
             thread.join(timeout=10)
 
 
-@pytest.mark.parametrize("task_class", [RequestCancelTask, StateCancelTask])
+@pytest.mark.parametrize("task_class", [RequestCancelTask, InterruptCancelTask])
 def test_abort_leaves_outputs_undefined(
     ewoksorange_qtapp, executor_context_factory, task_class
 ):
     """Cancellation observed by run(): it returns early, so no output is set.
 
-    Covers both interpretations of `Task.cancelled` (RequestCancelTask:
-    request, StateCancelTask: state).
+    Covers both ways of reacting to a stop request (RequestCancelTask:
+    polls `Task.stop_requested`, InterruptCancelTask: `Task._on_stop_requested`).
     """
     with executor_context_factory() as (kind, executor, recorder):
         inputs = {"duration": 2}
@@ -118,7 +118,7 @@ def test_abort_leaves_partial_outputs(ewoksorange_qtapp, executor_context_factor
 def test_abort_does_not_guarantee_cancellation(
     ewoksorange_qtapp, executor_context_factory
 ):
-    """A task that never checks `self.cancelled` always completes normally.
+    """A task that never checks `self.stop_requested` always completes normally.
 
     `aborted()` still reports True: it reflects that abort reached the task,
     not what the task chose to do about it.
diff --git a/src/ewoksorange/tests/owwidget/test_owwidget_parallel.py b/src/ewoksorange/tests/owwidget/test_owwidget_parallel.py
index 701b6b6c..fc44dae2 100644
--- a/src/ewoksorange/tests/owwidget/test_owwidget_parallel.py
+++ b/src/ewoksorange/tests/owwidget/test_owwidget_parallel.py
@@ -22,10 +22,6 @@ class Parallel(
     input_names=["value", "sleep", "synchronize_run"],
     output_names=["value", "time"],
 ):
-    def __init__(self, **kwargs):
-        super().__init__(**kwargs)
-        self.__cancel_requested = False
-
     def run(self):
         # Wait for all parallel task to start
         self.inputs.synchronize_run.wait(timeout=10)
@@ -36,18 +32,15 @@ def run(self):
         tm = time.perf_counter()
 
         # Return value as output or exception
-        if self.__cancel_requested:
-            try:
-                raise Cancelled(self.inputs.value, tm)
-            finally:
-                self.cancelled = True
+        if self.stop_requested:
+            raise Cancelled(self.inputs.value, tm)
 
         self.outputs.time = tm
         self.outputs.value = self.inputs.value
 
-    def cancel(self):
-        # Interpretation #1: self.cancelled is the state not the request
-        self.__cancel_requested = True
+    def _on_stop_requested(self):
+        # Nothing to do: `run()` checks `self.stop_requested`.
+        pass
 
 
 class OWParallel(