diff --git a/studio/backend/core/inference/sd_cpp_backend.py b/studio/backend/core/inference/sd_cpp_backend.py
index fd56c7ed86..09d144f58e 100644
--- a/studio/backend/core/inference/sd_cpp_backend.py
+++ b/studio/backend/core/inference/sd_cpp_backend.py
@@ -700,9 +700,7 @@ class SdCppDiffusionBackend:
             # Same per-variant encoder selection as _asset_specs, keyed on the loaded repo id, so the
             # cache-deletion guard protects the encoder repo this load actually downloaded (the 9B
             # variant's Qwen3-8B, not the 4B default).
-            repos.extend(
-                terepo for terepo, _f, _k in sd_cpp_text_encoders_for(fam, state.repo_id)
-            )
+            repos.extend(terepo for terepo, _f, _k in sd_cpp_text_encoders_for(fam, state.repo_id))
             return tuple(dict.fromkeys(r for r in repos if r))
 
     # ── Generate ───────────────────────────────────────────────────────────
diff --git a/studio/backend/tests/test_diffusion_lora_trainer.py b/studio/backend/tests/test_diffusion_lora_trainer.py
index d96c06641e..eeca048655 100644
--- a/studio/backend/tests/test_diffusion_lora_trainer.py
+++ b/studio/backend/tests/test_diffusion_lora_trainer.py
@@ -108,7 +108,7 @@ def test_discover_tolerates_non_object_and_invalid_utf8_jsonl(tmp_path):
     # must be skipped per-line rather than crash the trainer in .get(); a valid row still resolves.
     _touch(tmp_path / "x.png")
     (tmp_path / "metadata.jsonl").write_text(
-        "[]\nnull\n\"str\"\n123\n{not json\n"
+        '[]\nnull\n"str"\n123\n{not json\n'
         + json.dumps({"file_name": "x.png", "text": "hi"})
         + "\n",
         encoding = "utf-8",
diff --git a/studio/backend/tests/test_diffusion_training.py b/studio/backend/tests/test_diffusion_training.py
index c61eba3de5..22003af1ee 100644
--- a/studio/backend/tests/test_diffusion_training.py
+++ b/studio/backend/tests/test_diffusion_training.py
@@ -1045,9 +1045,7 @@ def test_diffusion_info_tolerates_non_object_jsonl(client, dataset_roots):
         b"null\n"
         b'"just a string"\n'
         b"123\n"
-        b"{not json\n"
-        + json.dumps({"file_name": "a.png", "text": "cap a"}).encode("utf-8")
-        + b"\n"
+        b"{not json\n" + json.dumps({"file_name": "a.png", "text": "cap a"}).encode("utf-8") + b"\n"
     )
     r = client.get("/api/train/diffusion/info")
     assert r.status_code == 200, r.text
@@ -1082,9 +1080,7 @@ def test_diffusion_dataset_mutations_blocked_while_training_active(client, datas
         files = [("files", ("b.png", b"x", "image/png"))],
     )
     assert up.status_code == 409, up.text
-    cap = client.put(
-        "/api/train/diffusion/dataset/locked/caption/a.png", json = {"caption": "hi"}
-    )
+    cap = client.put("/api/train/diffusion/dataset/locked/caption/a.png", json = {"caption": "hi"})
     assert cap.status_code == 409, cap.text
     dele = client.delete("/api/train/diffusion/dataset/locked/image/a.png")
     assert dele.status_code == 409, dele.text