diff --git a/strix/config/settings.py b/strix/config/settings.py
index ecea8e50..91fbdef1 100644
--- a/strix/config/settings.py
+++ b/strix/config/settings.py
@@ -50,6 +50,7 @@ class RuntimeSettings(BaseSettings):
     # Hard cap on a local target's size before we refuse to stream it into the
     # sandbox file-by-file (the SDK copies every file individually, which stalls
     # on large repos). Above this, the user must bind-mount via ``--mount``.
+    # Set to 0 (or less) to disable the pre-flight check entirely.
     max_local_copy_mb: int = Field(default=1024, alias="STRIX_MAX_LOCAL_COPY_MB")
 
 
diff --git a/strix/interface/utils.py b/strix/interface/utils.py
index fbde4c2c..95a70f04 100644
--- a/strix/interface/utils.py
+++ b/strix/interface/utils.py
@@ -1239,8 +1239,11 @@ def find_oversized_local_targets(
     """Return ``(path, size_bytes)`` for non-mounted local targets over ``max_bytes``.
 
     Mounted targets are bind-mounted rather than copied, so their size is
-    irrelevant and they are excluded.
+    irrelevant and they are excluded. A ``max_bytes`` of zero or less disables
+    the check entirely (returns no targets).
     """
+    if max_bytes <= 0:
+        return []
     oversized: list[tuple[str, int]] = []
     for target in targets_info:
         if target.get("type") != "local_code":
diff --git a/tests/test_local_sources.py b/tests/test_local_sources.py
index 2b0cd2a6..1cda1767 100644
--- a/tests/test_local_sources.py
+++ b/tests/test_local_sources.py
@@ -70,7 +70,14 @@ def test_find_oversized_ignores_mounted_targets(tmp_path: Path) -> None:
 
 def test_find_oversized_ignores_non_local_targets() -> None:
     targets = [{"type": "web_application", "details": {"target_url": "https://x"}}]
-    assert find_oversized_local_targets(targets, max_bytes=0) == []
+    assert find_oversized_local_targets(targets, max_bytes=1) == []
+
+
+@pytest.mark.parametrize("disabled", [0, -1])
+def test_find_oversized_disabled_for_non_positive_limit(tmp_path: Path, disabled: int) -> None:
+    _write_file(tmp_path / "big.bin", 500)
+    targets = [_local_target(str(tmp_path))]
+    assert find_oversized_local_targets(targets, max_bytes=disabled) == []
 
 
 def test_collect_local_sources_propagates_mount_flag() -> None: