diff --git a/src/lean_spec/forks/lstar/containers/attestation/attestation.py b/src/lean_spec/forks/lstar/containers/attestation/attestation.py
index 13ff4c0d..a98f8fb6 100644
--- a/src/lean_spec/forks/lstar/containers/attestation/attestation.py
+++ b/src/lean_spec/forks/lstar/containers/attestation/attestation.py
@@ -11,8 +11,6 @@
 Attestations can be aggregated by common data to save space and bandwidth.
 """
 
-from __future__ import annotations
-
 from lean_spec.subspecs.xmss.aggregation import TypeOneMultiSignature
 from lean_spec.subspecs.xmss.containers import Signature
 from lean_spec.types import AggregationBits, Checkpoint, Container, Slot, ValidatorIndex
diff --git a/src/lean_spec/forks/lstar/containers/block/types.py b/src/lean_spec/forks/lstar/containers/block/types.py
index b456681e..07594a75 100644
--- a/src/lean_spec/forks/lstar/containers/block/types.py
+++ b/src/lean_spec/forks/lstar/containers/block/types.py
@@ -1,7 +1,5 @@
 """Block-specific SSZ types for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
-
 from lean_spec.subspecs.chain.config import VALIDATOR_REGISTRY_LIMIT
 from lean_spec.types import SSZList
 
diff --git a/src/lean_spec/forks/lstar/containers/state/state.py b/src/lean_spec/forks/lstar/containers/state/state.py
index 4b42023d..38e69149 100644
--- a/src/lean_spec/forks/lstar/containers/state/state.py
+++ b/src/lean_spec/forks/lstar/containers/state/state.py
@@ -1,7 +1,5 @@
 """State Container for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
-
 from lean_spec.forks.lstar.containers.block import BlockHeader
 from lean_spec.forks.lstar.containers.config import Config
 from lean_spec.forks.lstar.containers.state.types import (
diff --git a/src/lean_spec/forks/lstar/containers/state/types.py b/src/lean_spec/forks/lstar/containers/state/types.py
index 02bc6007..8c40aa48 100644
--- a/src/lean_spec/forks/lstar/containers/state/types.py
+++ b/src/lean_spec/forks/lstar/containers/state/types.py
@@ -1,6 +1,6 @@
 """State-specific SSZ types for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
+from typing import Self
 
 from lean_spec.subspecs.chain.config import HISTORICAL_ROOTS_LIMIT, VALIDATOR_REGISTRY_LIMIT
 from lean_spec.types import Boolean, Bytes32, Slot, SSZList
@@ -67,7 +67,7 @@ def with_justified(
         finalized_slot: Slot,
         target_slot: Slot,
         value: Boolean,
-    ) -> JustifiedSlots:
+    ) -> Self:
         """
         Return a new bitfield with the justification status updated.
 
@@ -112,7 +112,7 @@ def with_justified(
 
         return self.model_copy(update={"data": new_data})
 
-    def extend_to_slot(self, finalized_slot: Slot, target_slot: Slot) -> JustifiedSlots:
+    def extend_to_slot(self, finalized_slot: Slot, target_slot: Slot) -> Self:
         """
         Extend the tracking capacity to cover a new target slot.
 
@@ -147,7 +147,7 @@ def extend_to_slot(self, finalized_slot: Slot, target_slot: Slot) -> JustifiedSl
         # We extend the existing data with False values to bridge the gap.
         return self.model_copy(update={"data": list(self.data) + [Boolean(False)] * gap_size})
 
-    def shift_window(self, delta: int) -> JustifiedSlots:
+    def shift_window(self, delta: int) -> Self:
         """
         Advance the tracking window by dropping slots that became finalized.
 
diff --git a/src/lean_spec/forks/lstar/containers/validator.py b/src/lean_spec/forks/lstar/containers/validator.py
index b4392659..835f5ff6 100644
--- a/src/lean_spec/forks/lstar/containers/validator.py
+++ b/src/lean_spec/forks/lstar/containers/validator.py
@@ -1,7 +1,5 @@
 """Validator container for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
-
 from lean_spec.subspecs.chain.config import VALIDATOR_REGISTRY_LIMIT
 from lean_spec.subspecs.xmss.containers import PublicKey
 from lean_spec.types import Bytes52, Container, SSZList, ValidatorIndex
diff --git a/src/lean_spec/subspecs/xmss/rand.py b/src/lean_spec/subspecs/xmss/rand.py
index 040faa07..fa84e80c 100644
--- a/src/lean_spec/subspecs/xmss/rand.py
+++ b/src/lean_spec/subspecs/xmss/rand.py
@@ -1,7 +1,5 @@
 """Random data generator for the XMSS signature scheme."""
 
-from __future__ import annotations
-
 import secrets
 
 from lean_spec.types import StrictBaseModel