diff --git a/radicale/tests/test_server.py b/radicale/tests/test_server.py
index 9de2680..3254ae7 100644
--- a/radicale/tests/test_server.py
+++ b/radicale/tests/test_server.py
@@ -110,9 +110,6 @@ class TestBaseServerRequests:
     def test_ipv6(self):
         if not server.HAS_IPV6:
             pytest.skip("IPv6 not supported")
-        if os.name == "nt" and server.EAI_ADDRFAMILY is None:
-            # HACK: incomplete errno conversion in WINE
-            server.EAI_ADDRFAMILY = -9
         with socket.socket(socket.AF_INET6, socket.SOCK_STREAM) as sock:
             sock.setsockopt(server.IPPROTO_IPV6, server.IPV6_V6ONLY, 1)
             try:
@@ -122,6 +119,13 @@ class TestBaseServerRequests:
                 pytest.skip("IPv6 not supported")
             self.sockname = sock.getsockname()[:2]
             self.configuration["server"]["hosts"] = "[%s]:%d" % self.sockname
-        self.thread.start()
-        status, _, _ = self.request("GET", "/")
+        savedEaiAddrfamily = server.EAI_ADDRFAMILY
+        if os.name == "nt" and server.EAI_ADDRFAMILY is None:
+            # HACK: incomplete errno conversion in WINE
+            server.EAI_ADDRFAMILY = -9
+        try:
+            self.thread.start()
+            status, _, _ = self.request("GET", "/")
+        finally:
+            server.EAI_ADDRFAMILY = savedEaiAddrfamily
         assert status == 302