diff --git a/optuna/artifacts/_backoff.py b/optuna/artifacts/_backoff.py
index 5633f74e0b..823a9c62b2 100644
--- a/optuna/artifacts/_backoff.py
+++ b/optuna/artifacts/_backoff.py
@@ -112,6 +112,6 @@ def remove(self, artifact_id: str) -> None:
 if TYPE_CHECKING:
     # A mypy-runtime assertion to ensure that the Backoff middleware implements
     # all abstract methods in ArtifactStore.
-    from optuna.artifacts._filesystem import FileSystemArtifactStore
+    from optuna.artifacts import FileSystemArtifactStore
 
     _: ArtifactStore = Backoff(FileSystemArtifactStore("."))