diff --git a/cylc/flow/task_queues/independent.py b/cylc/flow/task_queues/independent.py
index d423a5f1702..185edee4f2b 100644
--- a/cylc/flow/task_queues/independent.py
+++ b/cylc/flow/task_queues/independent.py
@@ -18,11 +18,13 @@
 
 from collections import deque
 from contextlib import suppress
-from typing import List, Set, Dict, Counter, Any
+from typing import TYPE_CHECKING, List, Set, Dict, Counter, Any
 
-from cylc.flow.task_proxy import TaskProxy
 from cylc.flow.task_queues import TaskQueueManagerBase
 
+if TYPE_CHECKING:
+    from cylc.flow.task_proxy import TaskProxy
+
 
 class LimitedTaskQueue:
     """One task queue with group members and active limit."""
@@ -33,16 +35,16 @@ def __init__(self, limit: int, members: Set[str]) -> None:
         self.members = members  # member task names
         self.deque: deque = deque()
 
-    def push_task(self, itask: TaskProxy) -> None:
+    def push_task(self, itask: 'TaskProxy') -> None:
         """Queue task if in my membership list."""
         if itask.tdef.name in self.members:
             self.deque.appendleft(itask)
 
-    def release(self, active: Counter[str]) -> List[TaskProxy]:
+    def release(self, active: Counter[str]) -> List['TaskProxy']:
         """Release tasks if below the active limit."""
         # The "active" argument counts active tasks by name.
-        released: List[TaskProxy] = []
-        held: List[TaskProxy] = []
+        released: List['TaskProxy'] = []
+        held: List['TaskProxy'] = []
         n_active: int = 0
         for mem in self.members:
             n_active += active[mem]
@@ -62,7 +64,7 @@ def release(self, active: Counter[str]) -> List[TaskProxy]:
             self.deque.appendleft(itask)
         return released
 
-    def remove(self, itask: TaskProxy) -> bool:
+    def remove(self, itask: 'TaskProxy') -> bool:
         """Remove a single task from queue, return True if removed."""
         try:
             self.deque.remove(itask)
@@ -111,30 +113,30 @@ def __init__(self,
                 config["limit"], config["members"]
             )
 
-        self.force_released: Set[TaskProxy] = set()
+        self.force_released: Set['TaskProxy'] = set()
 
-    def push_task(self, itask: TaskProxy) -> None:
+    def push_task(self, itask: 'TaskProxy') -> None:
         """Push a task to the appropriate queue."""
         for queue in self.queues.values():
             queue.push_task(itask)
 
-    def release_tasks(self, active: Counter[str]) -> List[TaskProxy]:
+    def release_tasks(self, active: Counter[str]) -> List['TaskProxy']:
         """Release tasks up to the queue limits."""
-        released: List[TaskProxy] = []
+        released: List['TaskProxy'] = []
         for queue in self.queues.values():
             released += queue.release(active)
         if self.force_released:
-            released += list(self.force_released)
+            released.extend(self.force_released)
             self.force_released = set()
         return released
 
-    def remove_task(self, itask: TaskProxy) -> None:
+    def remove_task(self, itask: 'TaskProxy') -> None:
         """Remove a task from whichever queue it belongs to."""
         for queue in self.queues.values():
             if queue.remove(itask):
                 break
 
-    def force_release_task(self, itask: TaskProxy) -> None:
+    def force_release_task(self, itask: 'TaskProxy') -> None:
         """Remove a task from whichever queue it belongs to.
 
         To be returned when release_tasks() is next called.
diff --git a/tests/unit/test_indep_task_queues.py b/tests/unit/test_indep_task_queues.py
index a0a1894cece..d144f58eecf 100644
--- a/tests/unit/test_indep_task_queues.py
+++ b/tests/unit/test_indep_task_queues.py
@@ -21,8 +21,8 @@
 
 import pytest
 
+from cylc.flow.task_proxy import TaskProxy
 from cylc.flow.task_queues.independent import IndepQueueManager
-from cylc.flow.task_state import TASK_STATUS_PREPARING
 
 
 MEMBERS = {"a", "b", "c", "d", "e", "f"}
@@ -61,9 +61,7 @@
 
 
 @pytest.mark.parametrize(
-    "active,"
-    "expected_released,"
-    "expected_foo_groups",
+    "active, expected_released, expected_foo_groups",
     [
         (
             Counter(["b1", "b2", "s1", "o1"]),
@@ -73,28 +71,24 @@
     ]
 )
 def test_queue_and_release(
-        active,
-        expected_released,
-        expected_foo_groups):
+    active,
+    expected_released,
+    expected_foo_groups
+):
     """Test task queue and release."""
     # configure the queue
     queue_mgr = IndepQueueManager(QCONFIG, ALL_TASK_NAMES, DESCENDANTS)
 
     # add newly ready tasks to the queue
     for name in READY_TASK_NAMES:
-        itask = Mock()
+        itask = Mock(spec=TaskProxy)
         itask.tdef.name = name
         itask.state.is_held = False
         queue_mgr.push_task(itask)
 
     # release tasks, given current active task counter
     released = queue_mgr.release_tasks(active)
-    assert sorted([r.tdef.name for r in released]) == sorted(expected_released)
-
-    # check released tasks change state to "preparing", and not is_queued
-    for r in released:
-        assert r.state.reset.called_with(TASK_STATUS_PREPARING)
-        assert r.state.reset.called_with(is_queued=False)
+    assert sorted(r.tdef.name for r in released) == sorted(expected_released)
 
     # check that adopted orphans end up in the default queue
     orphans = ["orphan1", "orphan2"]