diff --git a/temporalio/worker/_workflow_instance.py b/temporalio/worker/_workflow_instance.py
index 378cfc011..866d37f7d 100644
--- a/temporalio/worker/_workflow_instance.py
+++ b/temporalio/worker/_workflow_instance.py
@@ -322,6 +322,7 @@ def activate(
 
         activation_err: Optional[Exception] = None
         try:
+            asyncio._set_running_loop(self)
             # Split into job sets with patches, then signals + updates, then
             # non-queries, then queries
             job_sets: List[
@@ -368,6 +369,8 @@ def activate(
                         "Ignoring exception while deleting workflow", exc_info=True
                     )
                 activation_err = None
+        finally:
+            asyncio._set_running_loop(None)
 
         # If we're deleting, there better be no more tasks. It is important for
         # the integrity of the system that we check this. If there are tasks
@@ -1732,37 +1735,32 @@ def _register_task(
             setattr(task, "_log_destroy_pending", False)
 
     def _run_once(self, *, check_conditions: bool) -> None:
-        try:
-            asyncio._set_running_loop(self)
-
-            # We instantiate the workflow class _inside_ here because __init__
-            # needs to run with this event loop set
-            if not self._object:
-                self._object = self._defn.cls()
-
-            # Run while there is anything ready
+        # We instantiate the workflow class _inside_ here because __init__
+        # needs to run with this event loop set
+        if not self._object:
+            self._object = self._defn.cls()
+
+        # Run while there is anything ready
+        while self._ready:
+            # Run and remove all ready ones
             while self._ready:
-                # Run and remove all ready ones
-                while self._ready:
-                    handle = self._ready.popleft()
-                    handle._run()
-
-                    # Must throw here if not deleting. Only really set inside
-                    # _run_top_level_workflow_function.
-                    if self._current_activation_error and not self._deleting:
-                        raise self._current_activation_error
-
-                # Check conditions which may add to the ready list. Also remove
-                # conditions whose futures have already cancelled (e.g. when
-                # timed out).
-                if check_conditions:
-                    self._conditions[:] = [
-                        t
-                        for t in self._conditions
-                        if not t[1].done() and not self._check_condition(*t)
-                    ]
-        finally:
-            asyncio._set_running_loop(None)
+                handle = self._ready.popleft()
+                handle._run()
+
+                # Must throw here if not deleting. Only really set inside
+                # _run_top_level_workflow_function.
+                if self._current_activation_error and not self._deleting:
+                    raise self._current_activation_error
+
+            # Check conditions which may add to the ready list. Also remove
+            # conditions whose futures have already cancelled (e.g. when
+            # timed out).
+            if check_conditions:
+                self._conditions[:] = [
+                    t
+                    for t in self._conditions
+                    if not t[1].done() and not self._check_condition(*t)
+                ]
 
     # This is used for the primary workflow function and signal handlers in
     # order to apply common exception handling to each