diff --git a/pyproject.toml b/pyproject.toml
index e43639f2..8638c570 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -80,6 +80,8 @@ main = "gunicorn.app.pasterapp:serve"
 norecursedirs = ["examples", "lib", "local", "src", "tests/docker"]
 testpaths = ["tests/"]
 addopts = "--assert=plain --cov=gunicorn --cov-report=xml"
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 filterwarnings = [
     # Eventlet patches select module, which breaks asyncio event loop cleanup
     # This is expected behavior when testing eventlet worker
diff --git a/tests/treq_asgi.py b/tests/treq_asgi.py
index ab7c7655..adad3560 100644
--- a/tests/treq_asgi.py
+++ b/tests/treq_asgi.py
@@ -209,13 +209,14 @@ class badrequest:
         self.fname = fname
         self.name = os.path.basename(fname)
 
-        with open(self.fname) as handle:
+        with open(self.fname, 'rb') as handle:
             self.data = handle.read()
-        self.data = self.data.replace("\n", "").replace("\\r\\n", "\r\n")
-        self.data = self.data.replace("\\0", "\000").replace("\\n", "\n").replace("\\t", "\t")
-        if "\\" in self.data:
-            raise AssertionError("Unexpected backslash in test data")
-        self.data = self.data.encode('latin1')
+        self.data = self.data.replace(b"\n", b"").replace(b"\\r\\n", b"\r\n")
+        self.data = self.data.replace(b"\\0", b"\000").replace(b"\\n", b"\n").replace(b"\\t", b"\t")
+        # Handle hex escape sequences for binary data (e.g., \x0D for bare CR)
+        self.data = decode_hex_escapes(self.data)
+        if b"\\" in self.data:
+            raise AssertionError("Unexpected backslash in test data - only handling HTAB, NUL, CRLF, and hex escapes")
 
     def send_all(self):
         yield self.data