diff --git a/okhttp/src/main/java/io/grpc/okhttp/OkHttpServerTransport.java b/okhttp/src/main/java/io/grpc/okhttp/OkHttpServerTransport.java
index 8fb74d3f1b5..84cec601ccb 100644
--- a/okhttp/src/main/java/io/grpc/okhttp/OkHttpServerTransport.java
+++ b/okhttp/src/main/java/io/grpc/okhttp/OkHttpServerTransport.java
@@ -106,6 +106,7 @@ final class OkHttpServerTransport implements ServerTransport,
   private final KeepAliveEnforcer keepAliveEnforcer;
 
   private final Object lock = new Object();
+  private final Object handShakeLock = new Object();
   @GuardedBy("lock")
   private boolean abruptShutdown;
   @GuardedBy("lock")
@@ -164,11 +165,13 @@ private void startIo(SerializingExecutor serializingExecutor) {
       // The socket implementation is lazily initialized, but had broken thread-safety 
       // for that laziness https://bugs.openjdk.org/browse/JDK-8278326. 
       // As a workaround, we lock to synchronize initialization with shutdown().
+      HandshakerSocketFactory.HandshakeResult result;
       synchronized (lock) {
         socket.setTcpNoDelay(true);
       }
-      HandshakerSocketFactory.HandshakeResult result =
-          config.handshakerSocketFactory.handshake(socket, Attributes.EMPTY);
+      synchronized (handShakeLock) {
+        result = config.handshakerSocketFactory.handshake(socket, Attributes.EMPTY);
+      }
       synchronized (lock) {
         this.socket = result.socket;
       }
diff --git a/okhttp/src/test/java/io/grpc/okhttp/OkHttpClientTransportTest.java b/okhttp/src/test/java/io/grpc/okhttp/OkHttpClientTransportTest.java
index 7347399bfe5..89ef8c6e8ce 100644
--- a/okhttp/src/test/java/io/grpc/okhttp/OkHttpClientTransportTest.java
+++ b/okhttp/src/test/java/io/grpc/okhttp/OkHttpClientTransportTest.java
@@ -18,6 +18,7 @@
 
 import static com.google.common.base.Charsets.UTF_8;
 import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.Truth.assertWithMessage;
 import static io.grpc.internal.ClientStreamListener.RpcProgress.MISCARRIED;
 import static io.grpc.internal.ClientStreamListener.RpcProgress.PROCESSED;
 import static io.grpc.internal.ClientStreamListener.RpcProgress.REFUSED;
@@ -114,6 +115,7 @@
 import java.util.logging.Level;
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import javax.net.SocketFactory;
 import okio.Buffer;
@@ -293,7 +295,10 @@ public void close() throws SecurityException {
     Buffer buffer = createMessageFrame(message);
     frameHandler().data(false, 3, buffer, (int) buffer.size(),
         (int) buffer.size());
-    assertThat(logs).hasSize(1);
+
+    assertWithMessage("log messages: "
+        + logs.stream().map(LogRecord::getMessage).collect(Collectors.toList()))
+        .that(logs).hasSize(1);
     log = logs.remove(0);
     assertThat(log.getMessage()).startsWith(Direction.INBOUND + " DATA: streamId=" + 3);
     assertThat(log.getLevel()).isEqualTo(Level.FINE);
diff --git a/okhttp/src/test/java/io/grpc/okhttp/TlsTest.java b/okhttp/src/test/java/io/grpc/okhttp/TlsTest.java
index a21360a89ba..ffc2486871a 100644
--- a/okhttp/src/test/java/io/grpc/okhttp/TlsTest.java
+++ b/okhttp/src/test/java/io/grpc/okhttp/TlsTest.java
@@ -117,6 +117,7 @@ public void mtls_succeeds() throws Exception {
     ManagedChannel channel = grpcCleanupRule.register(clientChannel(server, channelCreds));
 
     SimpleServiceGrpc.newBlockingStub(channel).unaryRpc(SimpleRequest.getDefaultInstance());
+    server.shutdown();
   }
 
   @Test
@@ -144,6 +145,7 @@ public void untrustedClient_fails() throws Exception {
     ManagedChannel channel = grpcCleanupRule.register(clientChannel(server, channelCreds));
 
     assertRpcFails(channel);
+    server.shutdown();
   }
 
   @Test
@@ -168,6 +170,7 @@ public void missingOptionalClientCert_succeeds() throws Exception {
     ManagedChannel channel = grpcCleanupRule.register(clientChannel(server, channelCreds));
 
     SimpleServiceGrpc.newBlockingStub(channel).unaryRpc(SimpleRequest.getDefaultInstance());
+    server.shutdown();
   }
 
   @Test
@@ -192,6 +195,7 @@ public void missingRequiredClientCert_fails() throws Exception {
     ManagedChannel channel = grpcCleanupRule.register(clientChannel(server, channelCreds));
 
     assertRpcFails(channel);
+    server.shutdown();
   }
 
   @Test
@@ -208,6 +212,7 @@ public void untrustedServer_fails() throws Exception {
     ManagedChannel channel = grpcCleanupRule.register(clientChannel(server, channelCreds));
 
     assertRpcFails(channel);
+    server.shutdown();
   }
 
   @Test
@@ -231,6 +236,7 @@ public void unmatchedServerSubjectAlternativeNames_fails() throws Exception {
         .build());
 
     assertRpcFails(channel);
+    server.shutdown();
   }
 
   @Test
@@ -255,6 +261,7 @@ public void hostnameVerifierTrusts_succeeds()
           .build());
 
     SimpleServiceGrpc.newBlockingStub(channel).unaryRpc(SimpleRequest.getDefaultInstance());
+    server.shutdown();
   }
 
   @Test
@@ -280,6 +287,7 @@ public void hostnameVerifierFails_fails()
 
     Status status = assertRpcFails(channel);
     assertThat(status.getCause()).isInstanceOf(SSLPeerUnverifiedException.class);
+    server.shutdown();
   }
 
   private static Server server(ServerCredentials creds) throws IOException {