diff --git a/tools/tests/mp_match_authentication_contract.py b/tools/tests/mp_match_authentication_contract.py
index 00dbdc68c..797289b05 100644
--- a/tools/tests/mp_match_authentication_contract.py
+++ b/tools/tests/mp_match_authentication_contract.py
@@ -486,7 +486,10 @@ def locate_msvc() -> tuple[Path, str] | None:
 def executable_contract() -> None:
     temp_root = ROOT / ".tmp"
     temp_root.mkdir(exist_ok=True)
-    with tempfile.TemporaryDirectory(prefix="match-auth-", dir=temp_root) as temp:
+    # The Windows ARM64 runners refuse to delete the just-run harness executable
+    # (WinError 5) after the checks pass; a leftover file in .tmp must not turn
+    # that pass into a failure.
+    with tempfile.TemporaryDirectory(prefix="match-auth-", dir=temp_root, ignore_cleanup_errors=True) as temp:
         temp_dir = Path(temp)
         harness = temp_dir / "match_authentication_contract.cpp"
         executable = temp_dir / "match_authentication_contract.exe"
diff --git a/tools/tests/mp_match_pause_contract.py b/tools/tests/mp_match_pause_contract.py
index 6e609890e..09bfd753b 100644
--- a/tools/tests/mp_match_pause_contract.py
+++ b/tools/tests/mp_match_pause_contract.py
@@ -372,7 +372,10 @@ def compile_deadline_harness() -> None:
 
     tmp_root = ROOT / ".tmp"
     tmp_root.mkdir(exist_ok=True)
-    with tempfile.TemporaryDirectory(prefix="mp-pause-contract-", dir=tmp_root) as raw:
+    # The Windows ARM64 runners refuse to delete the just-run harness executable
+    # (WinError 5) after the checks pass; a leftover file in .tmp must not turn
+    # that pass into a failure.
+    with tempfile.TemporaryDirectory(prefix="mp-pause-contract-", dir=tmp_root, ignore_cleanup_errors=True) as raw:
         temp = Path(raw)
         source = temp / "deadline_harness.cpp"
         source.write_text(
@@ -484,7 +487,10 @@ def compile_prediction_clock_harness() -> None:
     compiler = shutil.which("clang++") or shutil.which("g++") or shutil.which("c++")
     if compiler is None:
         raise AssertionError("client prediction clock check requires a C++ compiler")
-    with tempfile.TemporaryDirectory(prefix="mp-pause-prediction-", dir=ROOT / ".tmp") as raw:
+    # The Windows ARM64 runners refuse to delete the just-run harness executable
+    # (WinError 5) after the checks pass; a leftover file in .tmp must not turn
+    # that pass into a failure.
+    with tempfile.TemporaryDirectory(prefix="mp-pause-prediction-", dir=ROOT / ".tmp", ignore_cleanup_errors=True) as raw:
         temp = Path(raw)
         source, executable = temp / "prediction.cpp", temp / "prediction.exe"
         source.write_text(source_text, encoding="utf-8")
@@ -658,7 +664,10 @@ def compile_match_clock_harness() -> None:
 
     tmp_root = ROOT / ".tmp"
     tmp_root.mkdir(exist_ok=True)
-    with tempfile.TemporaryDirectory(prefix="mp-match-clock-", dir=tmp_root) as raw:
+    # The Windows ARM64 runners refuse to delete the just-run harness executable
+    # (WinError 5) after the checks pass; a leftover file in .tmp must not turn
+    # that pass into a failure.
+    with tempfile.TemporaryDirectory(prefix="mp-match-clock-", dir=tmp_root, ignore_cleanup_errors=True) as raw:
         temp = Path(raw)
         source = temp / "match_clock_harness.cpp"
         source.write_text(MATCH_CLOCK_HARNESS.lstrip(), encoding="utf-8", newline="\n")
diff --git a/tools/tests/mp_match_teams_contract.py b/tools/tests/mp_match_teams_contract.py
index 9b6d06664..9dedd5e51 100644
--- a/tools/tests/mp_match_teams_contract.py
+++ b/tools/tests/mp_match_teams_contract.py
@@ -812,7 +812,10 @@ def locate_msvc() -> tuple[Path, str] | None:
 def executable_contract() -> None:
     temp_root = ROOT / ".tmp"
     temp_root.mkdir(exist_ok=True)
-    with tempfile.TemporaryDirectory(prefix="match-teams-", dir=temp_root) as temp:
+    # The Windows ARM64 runners refuse to delete the just-run harness executable
+    # (WinError 5) after the checks pass; a leftover file in .tmp must not turn
+    # that pass into a failure.
+    with tempfile.TemporaryDirectory(prefix="match-teams-", dir=temp_root, ignore_cleanup_errors=True) as temp:
         temp_dir = Path(temp)
         harness = temp_dir / "match_teams_contract.cpp"
         executable = temp_dir / "match_teams_contract.exe"