diff --git a/backend/services/hf_cache_repair.py b/backend/services/hf_cache_repair.py
index fa82f085..9fe30b17 100644
--- a/backend/services/hf_cache_repair.py
+++ b/backend/services/hf_cache_repair.py
@@ -238,9 +238,11 @@ def repair_repo_cache(repo_id: str, cache_dir: str | None = None) -> dict:
 
         from huggingface_hub import snapshot_download
 
-        dl_kwargs: dict = {"repo_id": repo_id, "revision": revision}
-        if cache_dir:
-            dl_kwargs["cache_dir"] = cache_dir
+        dl_kwargs: dict = {
+            "repo_id": repo_id,
+            "revision": revision,
+            "cache_dir": cache_root,
+        }
         endpoint = os.environ.get("HF_ENDPOINT")
         if endpoint:
             dl_kwargs["endpoint"] = endpoint
diff --git a/backend/services/model_manager.py b/backend/services/model_manager.py
index 82ff30f3..2c432b6a 100644
--- a/backend/services/model_manager.py
+++ b/backend/services/model_manager.py
@@ -1665,12 +1665,17 @@ def _repair_model_cache(checkpoint: str, *, force: bool = False) -> bool:
     try:
         from services.hf_cache_repair import hf_cache_home
         from services.hf_revisions import installed_revision
-        revision = installed_revision(checkpoint, hf_cache_home())
+        cache_root = hf_cache_home()
+        revision = installed_revision(checkpoint, cache_root)
     except (OSError, ValueError) as revision_err:
         _last_repair_error = str(revision_err)
         logger.warning("Refusing unpinned model repair for %s: %s", checkpoint, revision_err)
         return False
-    dl_kwargs: dict = {"repo_id": checkpoint, "revision": revision}
+    dl_kwargs: dict = {
+        "repo_id": checkpoint,
+        "revision": revision,
+        "cache_dir": cache_root,
+    }
     # Explicit endpoint (HF_ENDPOINT / pref) wins; otherwise the automatic
     # endpoint selection's cached pick applies (services.endpoint_race).
     try:
diff --git a/tests/test_hf_cache_repair.py b/tests/test_hf_cache_repair.py
index 8f3c0149..2e271852 100644
--- a/tests/test_hf_cache_repair.py
+++ b/tests/test_hf_cache_repair.py
@@ -148,11 +148,11 @@ def test_repair_removes_only_broken_and_redownloads(tmp_path, monkeypatch):
     _symlink_or_skip(os.path.join("..", "..", "blobs", "MISSING"),
                      str(snap / "model.safetensors"))
     calls = []
+    monkeypatch.setenv("HF_HUB_CACHE", str(cache))
     monkeypatch.setattr(huggingface_hub, "snapshot_download",
                         lambda **k: calls.append(k))
 
-    summary = hf_cache_repair.repair_repo_cache("test/checkpoint",
-                                                cache_dir=str(cache))
+    summary = hf_cache_repair.repair_repo_cache("test/checkpoint")
     assert summary["found"] == 1
     assert summary["removed"] == 1
     assert summary["restored"] is True
diff --git a/tests/test_model_cache_repair.py b/tests/test_model_cache_repair.py
index 807cc471..08605370 100644
--- a/tests/test_model_cache_repair.py
+++ b/tests/test_model_cache_repair.py
@@ -191,7 +191,7 @@ def test_repair_skipped_in_offline_mode(model_manager, monkeypatch):
     assert called == []  # no download attempted offline
 
 
-def test_repair_invokes_snapshot_download(model_manager, monkeypatch):
+def test_repair_invokes_snapshot_download(model_manager, monkeypatch, tmp_path):
     """Repair re-fetches the repo via snapshot_download (resume/fill missing)."""
     calls = []
 
@@ -200,11 +200,13 @@ def test_repair_invokes_snapshot_download(model_manager, monkeypatch):
         return "/cache/test/checkpoint"
 
     import huggingface_hub
+    monkeypatch.setenv("HF_HUB_CACHE", str(tmp_path))
     monkeypatch.setattr(huggingface_hub, "snapshot_download", fake_snapshot_download)
 
     assert model_manager._repair_model_cache("test/checkpoint") is True
     assert calls and calls[0]["repo_id"] == "test/checkpoint"
     assert calls[0]["revision"] == "a" * 40
+    assert calls[0]["cache_dir"] == str(tmp_path)
 
 
 def test_repair_returns_false_when_download_fails(model_manager, monkeypatch):