diff --git a/msvs/liboio-test.vcxproj b/msvs/liboio-test.vcxproj
index 9b8fa0e3d..f4f8ad856 100644
--- a/msvs/liboio-test.vcxproj
+++ b/msvs/liboio-test.vcxproj
@@ -143,6 +143,7 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
     </ClCompile>
+    <ClCompile Include="..\test\test-async.c" />
     <ClCompile Include="..\test\test-delayed-accept.c" />
     <ClCompile Include="..\test\test-callback-stack.c" />
     <ClCompile Include="..\test\test-connection-fail.c" />
diff --git a/test/test-async.c b/test/test-async.c
new file mode 100644
index 000000000..c1b73f3c7
--- /dev/null
+++ b/test/test-async.c
@@ -0,0 +1,189 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "../oio.h"
+#include "task.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+
+static oio_handle_t prepare_handle;
+
+static oio_handle_t async1_handle;
+static oio_handle_t async2_handle;
+
+static int prepare_cb_called = 0;
+
+static int async1_cb_called = 0;
+static int async2_cb_called = 0;
+
+static int close_cb_called = 0;
+
+static uintptr_t thread1_id = 0;
+static uintptr_t thread2_id = 0;
+static uintptr_t thread3_id = 0;
+
+
+/* Thread 1 calls oio_async_send on async_handle_1 20 times. */
+void thread1_entry(void *arg) {
+  int i;
+
+  for (i = 0; i < 20; i++) {
+    oio_async_send(&async1_handle);
+    oio_sleep(50);
+  }
+}
+
+
+/* Thread 2 calls oio_async_send on async_handle_2 8 times. */
+void thread2_entry(void *arg) {
+  int i;
+
+  for (i = 0; i < 8; i++) {
+    oio_async_send(&async2_handle);
+    oio_sleep(50);
+  }
+}
+
+
+/* Thread 3 calls oio_async_send on async_handle_2 8 times
+ * after waiting half a second first.
+ */
+void thread3_entry(void *arg) {
+  int i;
+
+  oio_sleep(500);
+
+  for (i = 0; i < 8; i++) {
+    oio_async_send(&async2_handle);
+    oio_sleep(50);
+  }
+}
+
+
+static void close_cb(oio_handle_t* handle, int status) {
+  ASSERT(handle != NULL);
+  ASSERT(status == 0);
+
+  close_cb_called++;
+}
+
+
+static oio_buf alloc_cb(oio_handle_t* handle, size_t size) {
+  oio_buf buf = {0, 0};
+  FATAL("alloc should not be called");
+  return buf;
+}
+
+
+static void async1_cb(oio_handle_t* handle, int status) {
+  ASSERT(handle == &async1_handle);
+  ASSERT(status == 0);
+
+  async1_cb_called++;
+  printf("async1_cb #%d\n", async1_cb_called);
+
+  if (async1_cb_called == 20) {
+    oio_close(handle);
+  }
+}
+
+
+static void async2_cb(oio_handle_t* handle, int status) {
+  ASSERT(handle == &async2_handle);
+  ASSERT(status == 0);
+
+  async2_cb_called++;
+  printf("async2_cb #%d\n", async2_cb_called);
+
+  if (async2_cb_called == 16) {
+    oio_close(handle);
+  }
+}
+
+
+static void prepare_cb(oio_handle_t* handle, int status) {
+  int r;
+
+  ASSERT(handle == &prepare_handle);
+  ASSERT(status == 0);
+
+  switch (prepare_cb_called) {
+    case 0:
+      thread1_id = oio_create_thread(thread1_entry, NULL);
+      ASSERT(thread1_id != 0);
+      break;
+
+    case 1:
+      thread2_id = oio_create_thread(thread2_entry, NULL);
+      ASSERT(thread2_id != 0);
+      break;
+
+    case 2:
+      thread3_id = oio_create_thread(thread3_entry, NULL);
+      ASSERT(thread3_id != 0);
+      break;
+
+    case 3:
+      r = oio_close(handle);
+      ASSERT(r == 0);
+      break;
+
+    case 4:
+      FATAL("Should never get here");
+  }
+
+  prepare_cb_called++;
+}
+
+
+TEST_IMPL(async) {
+  int r;
+
+  oio_init(alloc_cb);
+
+  r = oio_prepare_init(&prepare_handle, close_cb, NULL);
+  ASSERT(r == 0);
+  r = oio_prepare_start(&prepare_handle, prepare_cb);
+  ASSERT(r == 0);
+
+  r = oio_async_init(&async1_handle, async1_cb, close_cb, NULL);
+  ASSERT(r == 0);
+  r = oio_async_init(&async2_handle, async2_cb, close_cb, NULL);
+  ASSERT(r == 0);
+
+  r = oio_run();
+  ASSERT(r == 0);
+
+  r = oio_wait_thread(thread1_id);
+  ASSERT(r == 0);
+  r = oio_wait_thread(thread2_id);
+  ASSERT(r == 0);
+  r = oio_wait_thread(thread3_id);
+  ASSERT(r == 0);
+
+  ASSERT(prepare_cb_called == 4);
+  ASSERT(async1_cb_called = 20);
+  ASSERT(async2_cb_called = 16);
+  ASSERT(close_cb_called == 3);
+
+  return 0;
+}
diff --git a/test/test-list.h b/test/test-list.h
index 16066c607..0cf3518b5 100644
--- a/test/test-list.h
+++ b/test/test-list.h
@@ -31,6 +31,7 @@ TEST_DECLARE   (connection_fail)
 TEST_DECLARE   (callback_stack)
 TEST_DECLARE   (timeout)
 TEST_DECLARE   (loop_handles)
+TEST_DECLARE   (async)
 TEST_DECLARE   (fail_always)
 TEST_DECLARE   (pass_always)
 HELPER_DECLARE (echo_server)
@@ -63,6 +64,8 @@ TASK_LIST_START
 
   TEST_ENTRY  (loop_handles)
 
+  TEST_ENTRY  (async)
+
 #if 0
   /* These are for testing the test runner. */
   TEST_ENTRY  (fail_always)