diff --git a/test/asynchronous/test_encryption.py b/test/asynchronous/test_encryption.py
index 3f3714eeb4..f29b0f824d 100644
--- a/test/asynchronous/test_encryption.py
+++ b/test/asynchronous/test_encryption.py
@@ -380,6 +380,7 @@ async def test_use_after_close(self):
         is_greenthread_patched(),
         "gevent and eventlet do not support POSIX-style forking.",
     )
+    @async_client_context.require_sync
     async def test_fork(self):
         opts = AutoEncryptionOpts(KMS_PROVIDERS, "keyvault.datakeys")
         client = await self.async_rs_or_single_client(auto_encryption_opts=opts)
diff --git a/test/test_encryption.py b/test/test_encryption.py
index 96d40c4a34..512c92f4d1 100644
--- a/test/test_encryption.py
+++ b/test/test_encryption.py
@@ -380,6 +380,7 @@ def test_use_after_close(self):
         is_greenthread_patched(),
         "gevent and eventlet do not support POSIX-style forking.",
     )
+    @client_context.require_sync
     def test_fork(self):
         opts = AutoEncryptionOpts(KMS_PROVIDERS, "keyvault.datakeys")
         client = self.rs_or_single_client(auto_encryption_opts=opts)