diff --git a/tests/studio/test_model_picker_contracts.py b/tests/studio/test_model_picker_contracts.py
index 3fa8abb764..71a3c7d659 100644
--- a/tests/studio/test_model_picker_contracts.py
+++ b/tests/studio/test_model_picker_contracts.py
@@ -699,6 +699,6 @@ def test_backfill_compares_server_keys_by_normalized_identity():
     assert "if (known.has(key)) { continue; }" in src
     # A variant never holds a colon, so the last one splits the key. Splitting on
     # the first would cut a Windows drive letter off every path id.
-    assert "key.lastIndexOf(\":\")" in src
+    assert 'key.lastIndexOf(":")' in src
     # Repo ids fold and POSIX paths do not, which is exactly what these do.
     assert "normalizeModelIdentity(" in src and "normalizeGgufVariantIdentity(" in src