diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnection.java b/service/src/main/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnection.java
index b836b90c6..ea656351a 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnection.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnection.java
@@ -298,6 +298,8 @@ public class WebSocketConnection implements MessageAvailabilityListener, Displac
           builder.setRelay(message.getRelay());
         }
 
+        builder.setServerGuid(message.getGuid().toString());
+
         final Envelope envelope = builder.build();
 
         if (envelope.getSerializedSize() > MAX_DESKTOP_MESSAGE_SIZE && isDesktopClient) {
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionIntegrationTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionIntegrationTest.java
index 925efd585..0a11cf507 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionIntegrationTest.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionIntegrationTest.java
@@ -6,6 +6,7 @@
 package org.whispersystems.textsecuregcm.websocket;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyList;
@@ -31,6 +32,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.stream.Collectors;
 import org.apache.commons.lang3.RandomStringUtils;
 import org.junit.After;
 import org.junit.Before;
@@ -39,6 +41,7 @@ import org.junit.Test;
 import org.mockito.ArgumentCaptor;
 import org.mockito.stubbing.Answer;
 import org.whispersystems.textsecuregcm.entities.MessageProtos;
+import org.whispersystems.textsecuregcm.entities.MessageProtos.Envelope;
 import org.whispersystems.textsecuregcm.metrics.PushLatencyManager;
 import org.whispersystems.textsecuregcm.push.ReceiptSender;
 import org.whispersystems.textsecuregcm.redis.AbstractRedisClusterTest;
@@ -122,7 +125,7 @@ public class WebSocketConnectionIntegrationTest extends AbstractRedisClusterTest
                 final MessageProtos.Envelope envelope = generateRandomMessage(UUID.randomUUID());
 
                 persistedMessages.add(envelope);
-                expectedMessages.add(envelope.toBuilder().clearServerGuid().build());
+                expectedMessages.add(envelope);
             }
 
             messagesDynamoDb.store(persistedMessages, account.getUuid(), device.getId());
@@ -133,7 +136,7 @@ public class WebSocketConnectionIntegrationTest extends AbstractRedisClusterTest
             final MessageProtos.Envelope envelope = generateRandomMessage(messageGuid);
 
             messagesCache.insert(messageGuid, account.getUuid(), device.getId(), envelope);
-            expectedMessages.add(envelope.toBuilder().clearServerGuid().build());
+            expectedMessages.add(envelope);
         }
 
         final WebSocketResponseMessage successResponse = mock(WebSocketResponseMessage.class);
@@ -185,11 +188,15 @@ public class WebSocketConnectionIntegrationTest extends AbstractRedisClusterTest
         final int persistedMessageCount = 207;
         final int cachedMessageCount = 173;
 
+        final List<MessageProtos.Envelope> expectedMessages = new ArrayList<>(persistedMessageCount + cachedMessageCount);
+
         {
             final List<MessageProtos.Envelope> persistedMessages = new ArrayList<>(persistedMessageCount);
 
             for (int i = 0; i < persistedMessageCount; i++) {
-                persistedMessages.add(generateRandomMessage(UUID.randomUUID()));
+                final MessageProtos.Envelope envelope = generateRandomMessage(UUID.randomUUID());
+                persistedMessages.add(envelope);
+                expectedMessages.add(envelope);
             }
 
             messagesDynamoDb.store(persistedMessages, account.getUuid(), device.getId());
@@ -197,15 +204,34 @@ public class WebSocketConnectionIntegrationTest extends AbstractRedisClusterTest
 
         for (int i = 0; i < cachedMessageCount; i++) {
             final UUID messageGuid = UUID.randomUUID();
-            messagesCache.insert(messageGuid, account.getUuid(), device.getId(), generateRandomMessage(messageGuid));
+            final MessageProtos.Envelope envelope = generateRandomMessage(messageGuid);
+            messagesCache.insert(messageGuid, account.getUuid(), device.getId(), envelope);
+
+            expectedMessages.add(envelope);
         }
 
         when(webSocketClient.sendRequest(eq("PUT"), eq("/api/v1/message"), anyList(), any())).thenReturn(CompletableFuture.failedFuture(new IOException("Connection closed")));
 
         webSocketConnection.processStoredMessages();
 
-        verify(webSocketClient, atMost(persistedMessageCount + cachedMessageCount)).sendRequest(eq("PUT"), eq("/api/v1/message"), anyList(), any());
+        //noinspection unchecked
+        ArgumentCaptor<Optional<byte[]>> messageBodyCaptor = ArgumentCaptor.forClass(Optional.class);
+
+        verify(webSocketClient, atMost(persistedMessageCount + cachedMessageCount)).sendRequest(eq("PUT"), eq("/api/v1/message"), anyList(), messageBodyCaptor.capture());
         verify(webSocketClient, never()).sendRequest(eq("PUT"), eq("/api/v1/queue/empty"), anyList(), eq(Optional.empty()));
+
+      final List<MessageProtos.Envelope> sentMessages = messageBodyCaptor.getAllValues().stream()
+          .map(Optional::get)
+          .map(messageBytes -> {
+              try {
+                  return Envelope.parseFrom(messageBytes);
+              } catch (InvalidProtocolBufferException e) {
+                  throw new RuntimeException(e);
+              }
+          })
+          .collect(Collectors.toList());
+
+      assertTrue(expectedMessages.containsAll(sentMessages));
     }
 
     private MessageProtos.Envelope generateRandomMessage(final UUID messageGuid) {