diff --git a/pyproject.toml b/pyproject.toml
index b153d4b..7548bc8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -85,6 +85,7 @@ ignore = [
     "SIM115", # allow open without context handler
     "SIM116", # allow if-else instead of dict lookup
     "B018",   # allow useless expression (standalone identifiers)
+    "TC004",  # allow imports in TYPE_CHECKING block (circular import prevention)
 ]
 
 [tool.ruff.lint.isort]
diff --git a/src/window/dock/animator.py b/src/window/dock/animator.py
index d574065..052b40a 100644
--- a/src/window/dock/animator.py
+++ b/src/window/dock/animator.py
@@ -1,11 +1,13 @@
-from typing import Optional
+from typing import TYPE_CHECKING, Optional
 
 from fabric.utils import GLib
 
-from .canvas import DockCanvas
 from .constants import ANIM_INTERVAL_MS, IDLE_THRESHOLD, LERP_FACTOR
 from .layout import DockLayout
 
+if TYPE_CHECKING:
+    from .canvas import DockCanvas
+
 
 class DockAnimator:
     def __init__(self, canvas: DockCanvas):
diff --git a/src/window/dock/layout.py b/src/window/dock/layout.py
index 9f4e101..283dcb2 100644
--- a/src/window/dock/layout.py
+++ b/src/window/dock/layout.py
@@ -1,7 +1,6 @@
 import math
-from typing import List, Tuple
+from typing import TYPE_CHECKING, List, Tuple
 
-from .canvas import DockItem
 from .constants import (
     BG_PADDING_H,
     BG_PADDING_V,
@@ -12,6 +11,9 @@ from .constants import (
     SIGMA_FACTOR,
 )
 
+if TYPE_CHECKING:
+    from .canvas import DockItem
+
 
 class DockLayout:
     @staticmethod