diff --git a/VERSION b/VERSION
index 43ded906259f..2e3a551febd8 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.13.5
+1.13.6
diff --git a/docs/root/intro/version_history.rst b/docs/root/intro/version_history.rst
index e3190e972992..5e7a542b054a 100644
--- a/docs/root/intro/version_history.rst
+++ b/docs/root/intro/version_history.rst
@@ -1,6 +1,12 @@
 Version history
 ---------------
 
+1.13.6 (September 29, 2020)
+===========================
+Changes
+-------
+* test: fix flaky test.
+
 1.13.5 (September 29, 2020)
 ===========================
 Changes
diff --git a/test/integration/api_listener_integration_test.cc b/test/integration/api_listener_integration_test.cc
index 0fa47eb8275c..7328d87ea3b9 100644
--- a/test/integration/api_listener_integration_test.cc
+++ b/test/integration/api_listener_integration_test.cc
@@ -4,6 +4,7 @@
 #include "test/test_common/environment.h"
 #include "test/test_common/utility.h"
 
+#include "absl/synchronization/notification.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
@@ -76,13 +77,15 @@ name: api_listener
   NiceMock<Http::MockStreamEncoder> stream_encoder_;
 };
 
+ACTION_P(Notify, notification) { notification->Notify(); }
+
 INSTANTIATE_TEST_SUITE_P(IpVersions, ApiListenerIntegrationTest,
                          testing::ValuesIn(TestEnvironment::getIpVersionsForTest()),
                          TestUtility::ipTestParamsToString);
 
 TEST_P(ApiListenerIntegrationTest, Basic) {
-  ConditionalInitializer test_ran;
-  test_server_->server().dispatcher().post([this, &test_ran]() -> void {
+  absl::Notification done;
+  test_server_->server().dispatcher().post([this, &done]() -> void {
     ASSERT_TRUE(test_server_->server().listenerManager().apiListener().has_value());
     ASSERT_EQ("api_listener", test_server_->server().listenerManager().apiListener()->get().name());
     ASSERT_TRUE(test_server_->server().listenerManager().apiListener()->get().http().has_value());
@@ -97,17 +100,15 @@ TEST_P(ApiListenerIntegrationTest, Basic) {
     Http::TestHeaderMapImpl expected_response_headers{{":status", "200"}};
     EXPECT_CALL(stream_encoder_, encodeHeaders(_, false));
     EXPECT_CALL(stream_encoder_, encodeData(_, false));
-    EXPECT_CALL(stream_encoder_, encodeData(BufferStringEqual(""), true));
+    EXPECT_CALL(stream_encoder_, encodeData(BufferStringEqual(""), true)).WillOnce(Notify(&done));
 
     // Send a headers-only request
     stream_decoder.decodeHeaders(
         Http::HeaderMapPtr(new Http::TestHeaderMapImpl{
             {":method", "GET"}, {":path", "/api"}, {":scheme", "http"}, {":authority", "host"}}),
         true);
-
-    test_ran.setReady();
   });
-  test_ran.waitReady();
+  ASSERT_TRUE(done.WaitForNotificationWithTimeout(absl::Seconds(1)));
 }
 
 } // namespace