diff --git a/tests/integration/test_stubs.py b/tests/integration/test_stubs.py
index 71c7f3b..23bf8ec 100644
--- a/tests/integration/test_stubs.py
+++ b/tests/integration/test_stubs.py
@@ -67,8 +67,8 @@ def test_original_decoded_response_is_not_modified(tmpdir, httpbin):
         assert 'gzip' == inside.headers['content-encoding']
 
         # They should effectively be the same response.
-        inside_headers = (h for h in inside.headers.items() if h[0] != 'Date')
-        outside_headers = (h for h in outside.getheaders() if h[0] != 'Date')
+        inside_headers = (h for h in inside.headers.items() if h[0].lower() != 'date')
+        outside_headers = (h for h in outside.getheaders() if h[0].lower() != 'date')
         assert set(inside_headers) == set(outside_headers)
         inside = zlib.decompress(inside.read(), 16+zlib.MAX_WBITS)
         outside = zlib.decompress(outside.read(), 16+zlib.MAX_WBITS)