diff --git a/src/test/java/com/google/devtools/build/lib/blackbox/bazel/DefaultToolsSetup.java b/src/test/java/com/google/devtools/build/lib/blackbox/bazel/DefaultToolsSetup.java
index 48394f478222fa..334ac63f9b8823 100644
--- a/src/test/java/com/google/devtools/build/lib/blackbox/bazel/DefaultToolsSetup.java
+++ b/src/test/java/com/google/devtools/build/lib/blackbox/bazel/DefaultToolsSetup.java
@@ -87,7 +87,11 @@ public void setup(BlackBoxTestContext context) throws IOException {
       }
     }
 
-    lines.add("common --enable_bzlmod");
+    if (OS.getCurrent() == OS.DARWIN) {
+      // Prefer ipv6 network on macOS
+      lines.add("startup --host_jvm_args=-Djava.net.preferIPv6Addresses=true");
+      lines.add("build --jvmopt=-Djava.net.preferIPv6Addresses");
+    }
 
     context.write(".bazelrc", lines);
   }
diff --git a/src/test/py/bazel/remote/cache_decompression_test.py b/src/test/py/bazel/remote/cache_decompression_test.py
index f297a0cd3acf45..e6ca6cde47c112 100644
--- a/src/test/py/bazel/remote/cache_decompression_test.py
+++ b/src/test/py/bazel/remote/cache_decompression_test.py
@@ -64,12 +64,21 @@ def do_GET(self):
     self.finish()
 
 
+class HTTPServerV6(HTTPServer):
+  address_family = socket.AF_INET6
+
+
 class CacheDecompressionTest(test_base.TestBase):
 
   def setUp(self):
     test_base.TestBase.setUp(self)
     server_port = self.GetFreeTCPPort()
-    self.httpd = HTTPServer(('localhost', server_port), MemoryStorageHandler)
+    if self.IsDarwin():
+      self.httpd = HTTPServerV6(
+          ('localhost', server_port), MemoryStorageHandler
+      )
+    else:
+      self.httpd = HTTPServer(('localhost', server_port), MemoryStorageHandler)
     self.httpd.storage = {}
     self.url = 'http://localhost:{}'.format(server_port)
     self.background = threading.Thread(target=self.httpd.serve_forever)
diff --git a/src/test/py/bazel/test_base.py b/src/test/py/bazel/test_base.py
index 9f8e7cb4d517f4..58069c80c95f9f 100644
--- a/src/test/py/bazel/test_base.py
+++ b/src/test/py/bazel/test_base.py
@@ -136,7 +136,10 @@ def setUp(self):
         if TestBase.IsDarwin():
           # For reducing SSD usage on our physical Mac machines.
           f.write('common --experimental_repository_cache_hardlinks\n')
-      f.write('common --enable_bzlmod\n')
+      if TestBase.IsDarwin():
+        # Prefer ipv6 network on macOS
+        f.write('startup --host_jvm_args=-Djava.net.preferIPv6Addresses=true\n')
+        f.write('build --jvmopt=-Djava.net.preferIPv6Addresses\n')
     self.CopyFile(
         self.Rlocation('io_bazel/src/test/tools/bzlmod/MODULE.bazel.lock'),
         'MODULE.bazel.lock',
diff --git a/src/test/shell/bazel/testing_server.py b/src/test/shell/bazel/testing_server.py
index e4255b46687394..74598fa751e11b 100644
--- a/src/test/shell/bazel/testing_server.py
+++ b/src/test/shell/bazel/testing_server.py
@@ -41,6 +41,10 @@
 import time
 
 
+class TCPServerV6(TCPServer):
+  address_family = socket.AF_INET6
+
+
 class Handler(BaseHTTPRequestHandler):
   """Handlers for testing HTTP server."""
   auth = False
@@ -152,7 +156,10 @@ def main(argv):
     while port is None:
       try:
         port = random.randrange(32760, 59760)
-        httpd = TCPServer(('', port), Handler)
+        if sys.platform == 'darwin':
+          httpd = TCPServerV6(('', port), Handler)
+        else:
+          httpd = TCPServer(('', port), Handler)
       except socket.error:
         port = None
     sys.stdout.write('%d\nstarted\n' % (port,))
diff --git a/src/test/shell/testenv.sh.tmpl b/src/test/shell/testenv.sh.tmpl
index 6db1a9997ce196..852c3db720ee47 100755
--- a/src/test/shell/testenv.sh.tmpl
+++ b/src/test/shell/testenv.sh.tmpl
@@ -341,6 +341,12 @@ EOF
     echo "testenv.sh: Using shared install base at $TEST_INSTALL_BASE."
     echo "startup --install_base=$TEST_INSTALL_BASE" >> $TEST_TMPDIR/bazelrc
   fi
+
+  if is_darwin; then
+    echo "Add flags to prefer ipv6 network"
+    echo "startup --host_jvm_args=-Djava.net.preferIPv6Addresses=true" >> $TEST_TMPDIR/bazelrc
+    echo "build --jvmopt=-Djava.net.preferIPv6Addresses" >> $TEST_TMPDIR/bazelrc
+  fi
 }
 
 function setup_android_sdk_support() {