diff --git a/libs/checkpoint-postgres/pyproject.toml b/libs/checkpoint-postgres/pyproject.toml
index 180166b86..864ba2c00 100644
--- a/libs/checkpoint-postgres/pyproject.toml
+++ b/libs/checkpoint-postgres/pyproject.toml
@@ -64,6 +64,7 @@ lint.select = [
   "UP", # pyupgrade
   "B",  # flake8-bugbear
   "I",  # isort
+  "PLC0415",  # import-outside-top-level
   "UP", # pyupgrade
 ]
 lint.ignore = ["E501", "B008"]
diff --git a/libs/checkpoint-postgres/tests/test_async.py b/libs/checkpoint-postgres/tests/test_async.py
index fd42146cf..ec941da90 100644
--- a/libs/checkpoint-postgres/tests/test_async.py
+++ b/libs/checkpoint-postgres/tests/test_async.py
@@ -380,13 +380,15 @@ async def test_delta_channel_chain_reconstruction(saver_name: str) -> None:
         "langgraph.channels.delta", reason="langgraph core not installed"
     )
 
-    from typing import Annotated
+    # Deferred on purpose: langgraph core is not a test dependency of this
+    # package, so these must stay behind the importorskip above.
+    from typing import Annotated  # noqa: PLC0415
 
-    from langchain_core.messages import AIMessage, HumanMessage
-    from langgraph.channels.delta import DeltaChannel
-    from langgraph.graph import START, StateGraph
-    from langgraph.graph.message import _messages_delta_reducer
-    from typing_extensions import TypedDict
+    from langchain_core.messages import AIMessage, HumanMessage  # noqa: PLC0415
+    from langgraph.channels.delta import DeltaChannel  # noqa: PLC0415
+    from langgraph.graph import START, StateGraph  # noqa: PLC0415
+    from langgraph.graph.message import _messages_delta_reducer  # noqa: PLC0415
+    from typing_extensions import TypedDict  # noqa: PLC0415
 
     class State(TypedDict):
         messages: Annotated[list, DeltaChannel(_messages_delta_reducer)]
diff --git a/libs/checkpoint-sqlite/pyproject.toml b/libs/checkpoint-sqlite/pyproject.toml
index c0a040655..a9d6c945f 100644
--- a/libs/checkpoint-sqlite/pyproject.toml
+++ b/libs/checkpoint-sqlite/pyproject.toml
@@ -62,6 +62,7 @@ lint.select = [
   "UP", # pyupgrade
   "B",  # flake8-bugbear
   "I",  # isort
+  "PLC0415",  # import-outside-top-level
   "UP", # pyupgrade
 ]
 lint.ignore = ["E501", "B008"]
diff --git a/libs/checkpoint-sqlite/tests/test_conformance_delta.py b/libs/checkpoint-sqlite/tests/test_conformance_delta.py
index ba0e90f18..d900855d1 100644
--- a/libs/checkpoint-sqlite/tests/test_conformance_delta.py
+++ b/libs/checkpoint-sqlite/tests/test_conformance_delta.py
@@ -10,14 +10,14 @@ pytest.importorskip(
 )
 pytest.importorskip("aiosqlite", reason="aiosqlite not installed")
 
+from langgraph.checkpoint.conformance import validate  # noqa: E402
+from langgraph.checkpoint.conformance.initializer import checkpointer_test  # noqa: E402
+
+from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver  # noqa: E402
+
 
 @pytest.mark.asyncio
 async def test_delta_channel_conformance():
-    from langgraph.checkpoint.conformance import validate
-    from langgraph.checkpoint.conformance.initializer import checkpointer_test
-
-    from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver
-
     @checkpointer_test(name="AsyncSqliteSaver")
     async def sqlite_saver():
         async with AsyncSqliteSaver.from_conn_string(":memory:") as saver:
diff --git a/libs/checkpoint-sqlite/tests/test_store.py b/libs/checkpoint-sqlite/tests/test_store.py
index e930208f1..d4b06847e 100644
--- a/libs/checkpoint-sqlite/tests/test_store.py
+++ b/libs/checkpoint-sqlite/tests/test_store.py
@@ -1,7 +1,11 @@
+import math
 import os
+import random
 import re
 import tempfile
+import time
 import uuid
+from collections import Counter, defaultdict
 from collections.abc import Generator, Iterable
 from contextlib import contextmanager
 from typing import Any, Literal, cast
@@ -33,10 +37,6 @@ class CharacterEmbeddings(Embeddings):
 
     def __init__(self, dims: int = 50, seed: int = 42):
         """Initialize with embedding dimensions and random seed."""
-        import math
-        import random
-        from collections import defaultdict
-
         self._rng = random.Random(seed)
         self.dims = dims
         # Create projection vector for each character lazily
@@ -48,9 +48,6 @@ class CharacterEmbeddings(Embeddings):
 
     def _embed_one(self, text: str) -> list[float]:
         """Embed a single text."""
-        import math
-        from collections import Counter
-
         counts = Counter(text)
         total = sum(counts.values())
 
@@ -338,8 +335,6 @@ class TestSqliteStore:
 
             # Test update
             # Small delay to ensure the updated timestamp is different
-            import time
-
             time.sleep(0.01)
 
             updated_value = {"title": "Updated Document", "content": "Hello, Updated!"}