diff --git a/cachecontrol/filewrapper.py b/cachecontrol/filewrapper.py
index 37d2fa5..efdfeee 100644
--- a/cachecontrol/filewrapper.py
+++ b/cachecontrol/filewrapper.py
@@ -117,3 +117,9 @@ def _safe_read(self, amt: int) -> bytes:
             self._close()
 
         return data
+
+    def close(self) -> None:
+        try:
+            self.__fp.close()
+        finally:
+            self.__buf.close()
diff --git a/pyproject.toml b/pyproject.toml
index 5b6910b..3986202 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -77,4 +77,6 @@ module = "msgpack"
 ignore_missing_imports = true
 
 [tool.pytest.ini_options]
+addopts = "--strict-markers --strict-config"
 norecursedirs = ["bin", "lib", "include", "build"]
+filterwarnings = ["error"]
diff --git a/tests/test_chunked_response.py b/tests/test_chunked_response.py
index 8cc4496..077bc66 100644
--- a/tests/test_chunked_response.py
+++ b/tests/test_chunked_response.py
@@ -50,7 +50,6 @@ def test_stream_is_cached(self, url, sess):
         assert content_1 == content_2
 
     def test_stream_is_not_cached_when_content_is_not_read(self, url, sess):
-        sess.get(url + "stream", stream=True)
-        resp = sess.get(url + "stream", stream=True)
-
-        assert not resp.from_cache
+        with sess.get(url + "stream", stream=True):
+            with sess.get(url + "stream", stream=True) as resp:
+                assert not resp.from_cache
diff --git a/tests/test_regressions.py b/tests/test_regressions.py
index 78e8aaa..7e4a76a 100644
--- a/tests/test_regressions.py
+++ b/tests/test_regressions.py
@@ -23,11 +23,12 @@ def test_file_cache_recognizes_consumed_file_handle(self, url):
 
 def test_getattr_during_gc():
     s = CallbackFileWrapper(None, None)
-    # normal behavior:
-    with pytest.raises(AttributeError):
-        s.x
-
-    # this previously had caused an infinite recursion
-    vars(s).clear()  # gc does this.
-    with pytest.raises(AttributeError):
-        s.x
+    with s._CallbackFileWrapper__buf:
+        # normal behavior:
+        with pytest.raises(AttributeError):
+            s.x
+
+        # this previously had caused an infinite recursion
+        vars(s).clear()  # gc does this.
+        with pytest.raises(AttributeError):
+            s.x