diff --git a/test/test_http11.py b/test/test_http11.py
index 21dd7f70..954bacd0 100644
--- a/test/test_http11.py
+++ b/test/test_http11.py
@@ -637,7 +637,7 @@ def test_response_transparently_decrypts_gzip(self):
         headers = {b'content-encoding': [b'gzip'], b'connection': [b'close']}
         r = HTTP11Response(200, 'OK', headers, d, None)
 
-        c = zlib_compressobj(wbits=24)
+        c = zlib_compressobj(wbits=25)
         body = c.compress(b'this is test data')
         body += c.flush()
         d._buffer = BytesIO(body)
@@ -719,7 +719,7 @@ def test_response_transparently_decrypts_chunked_gzip(self):
         }
         r = HTTP11Response(200, 'OK', headers, d, None)
 
-        c = zlib_compressobj(wbits=24)
+        c = zlib_compressobj(wbits=25)
         body = c.compress(b'this is test data')
         body += c.flush()
 
@@ -804,7 +804,7 @@ def test_bounded_read_expect_close_with_content_length(self):
     def test_compressed_bounded_read_expect_close(self):
         headers = {b'connection': [b'close'], b'content-encoding': [b'gzip']}
 
-        c = zlib_compressobj(wbits=24)
+        c = zlib_compressobj(wbits=25)
         body = c.compress(b'hello there sir')
         body += c.flush()
 
diff --git a/test/test_hyper.py b/test/test_hyper.py
index f4a5994d..7925ad65 100644
--- a/test/test_hyper.py
+++ b/test/test_hyper.py
@@ -1026,7 +1026,7 @@ def test_response_transparently_decrypts_gzip(self):
         headers = HTTPHeaderMap(
             [(':status', '200'), ('content-encoding', 'gzip')]
         )
-        c = zlib_compressobj(wbits=24)
+        c = zlib_compressobj(wbits=25)
         body = c.compress(b'this is test data')
         body += c.flush()
         resp = HTTP20Response(headers, DummyStream(body))
@@ -1144,7 +1144,7 @@ def test_read_compressed_frames(self):
         headers = HTTPHeaderMap(
             [(':status', '200'), ('content-encoding', 'gzip')]
         )
-        c = zlib_compressobj(wbits=24)
+        c = zlib_compressobj(wbits=25)
         body = c.compress(b'this is test data')
         body += c.flush()