diff --git a/cirq-core/cirq/ops/classically_controlled_operation.py b/cirq-core/cirq/ops/classically_controlled_operation.py
index 1f0301160de..abaff46a6ef 100644
--- a/cirq-core/cirq/ops/classically_controlled_operation.py
+++ b/cirq-core/cirq/ops/classically_controlled_operation.py
@@ -125,10 +125,7 @@ def with_qubits(self, *new_qubits):
             *self._conditions
         )
 
-    def _decompose_(self):
-        return self._decompose_with_context_()
-
-    def _decompose_with_context_(self, context: cirq.DecompositionContext | None = None):
+    def _decompose_with_context_(self, *, context: cirq.DecompositionContext):
         result = protocols.decompose_once(
             self._sub_operation, NotImplemented, flatten=False, context=context
         )
diff --git a/cirq-core/cirq/ops/controlled_gate.py b/cirq-core/cirq/ops/controlled_gate.py
index 4ed6a03b876..f57a57b60b7 100644
--- a/cirq-core/cirq/ops/controlled_gate.py
+++ b/cirq-core/cirq/ops/controlled_gate.py
@@ -139,11 +139,8 @@ def num_controls(self) -> int:
     def _qid_shape_(self) -> tuple[int, ...]:
         return self.control_qid_shape + protocols.qid_shape(self.sub_gate)
 
-    def _decompose_(self, qubits: tuple[cirq.Qid, ...]) -> None | NotImplementedType | cirq.OP_TREE:
-        return self._decompose_with_context_(qubits)
-
     def _decompose_with_context_(
-        self, qubits: tuple[cirq.Qid, ...], context: cirq.DecompositionContext | None = None
+        self, qubits: tuple[cirq.Qid, ...], *, context: cirq.DecompositionContext
     ) -> None | NotImplementedType | cirq.OP_TREE:
         control_qubits = list(qubits[: self.num_controls()])
         controlled_sub_gate = self.sub_gate.controlled(
diff --git a/cirq-core/cirq/ops/controlled_operation.py b/cirq-core/cirq/ops/controlled_operation.py
index b133b5c451a..e1fb0b604a6 100644
--- a/cirq-core/cirq/ops/controlled_operation.py
+++ b/cirq-core/cirq/ops/controlled_operation.py
@@ -134,10 +134,7 @@ def with_qubits(self, *new_qubits):
             new_qubits[:n], self.sub_operation.with_qubits(*new_qubits[n:]), self.control_values
         )
 
-    def _decompose_(self):
-        return self._decompose_with_context_()
-
-    def _decompose_with_context_(self, context: cirq.DecompositionContext | None = None):
+    def _decompose_with_context_(self, *, context: cirq.DecompositionContext):
         result = protocols.decompose_once_with_qubits(
             self.gate, self.qubits, NotImplemented, flatten=False, context=context
         )
diff --git a/cirq-core/cirq/ops/gate_operation.py b/cirq-core/cirq/ops/gate_operation.py
index 925bf262ed2..eceee35d5ac 100644
--- a/cirq-core/cirq/ops/gate_operation.py
+++ b/cirq-core/cirq/ops/gate_operation.py
@@ -148,11 +148,8 @@ def _qid_shape_(self):
     def _num_qubits_(self):
         return len(self._qubits)
 
-    def _decompose_(self) -> cirq.OP_TREE:
-        return self._decompose_with_context_()
-
     def _decompose_with_context_(
-        self, context: cirq.DecompositionContext | None = None
+        self, *, context: cirq.DecompositionContext
     ) -> cirq.OP_TREE:
         return protocols.decompose_once_with_qubits(
             self.gate, self.qubits, NotImplemented, flatten=False, context=context
diff --git a/cirq-core/cirq/ops/raw_types.py b/cirq-core/cirq/ops/raw_types.py
index c84a6928f02..3b7107d315d 100644
--- a/cirq-core/cirq/ops/raw_types.py
+++ b/cirq-core/cirq/ops/raw_types.py
@@ -828,11 +828,8 @@ def _from_json_dict_(cls, sub_operation, tags, **kwargs):
     def _json_dict_(self) -> dict[str, Any]:
         return protocols.obj_to_dict_helper(self, ['sub_operation', 'tags'])
 
-    def _decompose_(self) -> cirq.OP_TREE:
-        return self._decompose_with_context_()
-
     def _decompose_with_context_(
-        self, context: cirq.DecompositionContext | None = None
+        self, *, context: cirq.DecompositionContext
     ) -> cirq.OP_TREE:
         return protocols.decompose_once(
             self.sub_operation, default=None, flatten=False, context=context
@@ -986,7 +983,7 @@ def _decompose_(self, qubits):
         return self._decompose_with_context_(qubits)
 
     def _decompose_with_context_(
-        self, qubits: Sequence[cirq.Qid], context: cirq.DecompositionContext | None = None
+        self, qubits: Sequence[cirq.Qid], *, context: cirq.DecompositionContext
     ) -> cirq.OP_TREE:
         return protocols.inverse(
             protocols.decompose_once_with_qubits(self._original, qubits, context=context)
diff --git a/cirq-core/cirq/protocols/decompose_protocol.py b/cirq-core/cirq/protocols/decompose_protocol.py
index 3d552df311f..f8ea151f420 100644
--- a/cirq-core/cirq/protocols/decompose_protocol.py
+++ b/cirq-core/cirq/protocols/decompose_protocol.py
@@ -54,7 +54,7 @@
 @runtime_checkable
 class OpDecomposerWithContext(Protocol):
     def __call__(
-        self, __op: cirq.Operation, *, context: cirq.DecompositionContext | None = None
+        self, __op: cirq.Operation, *, context: cirq.DecompositionContext
     ) -> DecomposeResult: ...
 
 
@@ -126,7 +126,7 @@ def _decompose_(self) -> DecomposeResult:
         pass
 
     def _decompose_with_context_(
-        self, *, context: DecompositionContext | None = None
+        self, *, context: DecompositionContext
     ) -> DecomposeResult:
         pass
 
@@ -154,13 +154,13 @@ def _decompose_(self, qubits: tuple[cirq.Qid, ...]) -> DecomposeResult:
         pass
 
     def _decompose_with_context_(
-        self, qubits: tuple[cirq.Qid, ...], *, context: DecompositionContext | None = None
+        self, qubits: tuple[cirq.Qid, ...], *, context: DecompositionContext
     ) -> DecomposeResult:
         pass
 
 
 def _try_op_decomposer(
-    val: Any, decomposer: OpDecomposer | None, *, context: DecompositionContext | None = None
+    val: Any, decomposer: OpDecomposer | None, *, context: DecompositionContext
 ) -> DecomposeResult:
     if decomposer is None or not isinstance(val, ops.Operation):
         return None
@@ -173,7 +173,7 @@ def _try_op_decomposer(
 
 @dataclasses.dataclass(frozen=True)
 class _DecomposeArgs:
-    context: DecompositionContext | None
+    context: DecompositionContext
     intercepting_decomposer: OpDecomposer | None
     fallback_decomposer: OpDecomposer | None
     keep: Callable[[cirq.Operation], bool] | None
@@ -362,14 +362,9 @@ def decompose_once(
         TypeError: `val` didn't have a `_decompose_` method (or that method returned
             `NotImplemented` or `None`) and `default` wasn't set.
     """
-    if context is None:
-        context = DecompositionContext(
-            ops.SimpleQubitManager(prefix=f'_decompose_protocol_{next(_CONTEXT_COUNTER)}')
-        )
-
-    method = getattr(val, '_decompose_with_context_', None)
-    decomposed = NotImplemented if method is None else method(*args, **kwargs, context=context)
-    if decomposed is NotImplemented or decomposed is None:
+    if context is not None and hasattr(val, '_decompose_with_context_'):
+        decomposed = val._decompose_with_context_(*args, context=context, **kwargs)
+    else:
         method = getattr(val, '_decompose_', None)
         decomposed = NotImplemented if method is None else method(*args, **kwargs)