diff --git a/tests/test_benchmarks_cookie_helpers.py b/tests/test_benchmarks_cookie_helpers.py
new file mode 100644
index 00000000000..5a06a2d6b50
--- /dev/null
+++ b/tests/test_benchmarks_cookie_helpers.py
@@ -0,0 +1,28 @@
+"""codspeed benchmarks for cookie helpers."""
+
+from typing import TYPE_CHECKING
+
+import pytest
+
+from aiohttp._cookie_helpers import _COOKIE_PATTERN
+
+if TYPE_CHECKING:
+    from pytest_codspeed import BenchmarkFixture
+else:
+    pytest_codspeed = pytest.importorskip("pytest_codspeed")
+    BenchmarkFixture = pytest_codspeed.BenchmarkFixture
+
+
+def test_cookie_pattern_redos_payload(benchmark: BenchmarkFixture) -> None:
+    """Benchmark ``_COOKIE_PATTERN`` against a ReDoS payload.
+
+    A regression that reintroduces catastrophic backtracking shows up here as
+    a large, deterministic slowdown instead of a flaky wall-clock assertion.
+    """
+    value = "a" + "=" * 21651 + "\x00"
+    # This payload must not match.
+    assert _COOKIE_PATTERN.match(value) is None
+
+    @benchmark
+    def _run() -> None:
+        _COOKIE_PATTERN.match(value)
diff --git a/tests/test_cookie_helpers.py b/tests/test_cookie_helpers.py
index be6228d698f..91ed63c51bb 100644
--- a/tests/test_cookie_helpers.py
+++ b/tests/test_cookie_helpers.py
@@ -2,7 +2,6 @@
 
 import logging
 import sys
-import time
 from http.cookies import (
     CookieError,
     Morsel,
@@ -637,23 +636,6 @@ def test_cookie_pattern_matches_partitioned_attribute(test_string: str) -> None:
     assert match.group("key").lower() == "partitioned"
 
 
-def test_cookie_pattern_performance() -> None:
-    """Test that the cookie pattern doesn't suffer from ReDoS issues."""
-    COOKIE_PATTERN_TIME_THRESHOLD_SECONDS = 0.08
-    value = "a" + "=" * 21651 + "\x00"
-    start = time.perf_counter()
-    match = helpers._COOKIE_PATTERN.match(value)
-    elapsed = time.perf_counter() - start
-
-    # If this is taking more time, there's probably a performance/ReDoS issue.
-    assert elapsed < COOKIE_PATTERN_TIME_THRESHOLD_SECONDS, (
-        f"Pattern took {elapsed * 1000:.1f}ms, "
-        f"expected <{COOKIE_PATTERN_TIME_THRESHOLD_SECONDS * 1000:.0f}ms - potential ReDoS issue"
-    )
-    # This example shouldn't produce a match either.
-    assert match is None
-
-
 def test_parse_set_cookie_headers_issue_7993_double_quotes() -> None:
     """
     Test that cookies with unmatched opening quotes don't break parsing of subsequent cookies.