diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
index 333fbe971..7a6553fcc 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
@@ -165,6 +165,7 @@ import org.whispersystems.textsecuregcm.grpc.net.NoiseWebSocketTunnelServer;
 import org.whispersystems.textsecuregcm.jetty.JettyHttpConfigurationCustomizer;
 import org.whispersystems.textsecuregcm.keytransparency.KeyTransparencyServiceClient;
 import org.whispersystems.textsecuregcm.limits.CardinalityEstimator;
+import org.whispersystems.textsecuregcm.limits.MessageDeliveryLoopMonitor;
 import org.whispersystems.textsecuregcm.limits.PushChallengeManager;
 import org.whispersystems.textsecuregcm.limits.RateLimitChallengeManager;
 import org.whispersystems.textsecuregcm.limits.RateLimiters;
@@ -675,6 +676,8 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
         config.getDynamoDbTables().getRedeemedReceipts().getExpiration());
     Subscriptions subscriptions = new Subscriptions(
         config.getDynamoDbTables().getSubscriptions().getTableName(), dynamoDbAsyncClient);
+    MessageDeliveryLoopMonitor messageDeliveryLoopMonitor =
+        new MessageDeliveryLoopMonitor(rateLimitersCluster);
 
     final RegistrationLockVerificationManager registrationLockVerificationManager = new RegistrationLockVerificationManager(
         accountsManager, clientPresenceManager, svr2CredentialsGenerator, svr3CredentialsGenerator,
@@ -1015,7 +1018,7 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
     webSocketEnvironment.setConnectListener(
         new AuthenticatedConnectListener(receiptSender, messagesManager, messageMetrics, pushNotificationManager,
             pushNotificationScheduler, clientPresenceManager, websocketScheduledExecutor, messageDeliveryScheduler,
-            clientReleaseManager));
+            clientReleaseManager, messageDeliveryLoopMonitor));
     webSocketEnvironment.jersey()
         .register(new WebsocketRefreshApplicationEventListener(accountsManager, clientPresenceManager));
     webSocketEnvironment.jersey().register(new RequestStatisticsFilter(TrafficSource.WEBSOCKET));
@@ -1118,7 +1121,8 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
         new MessageController(rateLimiters, messageByteLimitCardinalityEstimator, messageSender, receiptSender,
             accountsManager, messagesManager, pushNotificationManager, pushNotificationScheduler, reportMessageManager,
             multiRecipientMessageExecutor, messageDeliveryScheduler, reportSpamTokenProvider, clientReleaseManager,
-            dynamicConfigurationManager, zkSecretParams, spamChecker, messageMetrics, Clock.systemUTC()),
+            dynamicConfigurationManager, zkSecretParams, spamChecker, messageMetrics, messageDeliveryLoopMonitor,
+            Clock.systemUTC()),
         new PaymentsController(currencyManager, paymentsCredentialsGenerator),
         new ProfileController(clock, rateLimiters, accountsManager, profilesManager, dynamicConfigurationManager,
             profileBadgeConverter, config.getBadges(), cdnS3Client, profileCdnPolicyGenerator, profileCdnPolicySigner,
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/MessageController.java b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/MessageController.java
index 90390b0cf..77791c152 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/MessageController.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/MessageController.java
@@ -106,6 +106,7 @@ import org.whispersystems.textsecuregcm.identity.AciServiceIdentifier;
 import org.whispersystems.textsecuregcm.identity.IdentityType;
 import org.whispersystems.textsecuregcm.identity.ServiceIdentifier;
 import org.whispersystems.textsecuregcm.limits.CardinalityEstimator;
+import org.whispersystems.textsecuregcm.limits.MessageDeliveryLoopMonitor;
 import org.whispersystems.textsecuregcm.limits.RateLimiters;
 import org.whispersystems.textsecuregcm.metrics.MessageMetrics;
 import org.whispersystems.textsecuregcm.metrics.MetricsUtil;
@@ -168,6 +169,7 @@ public class MessageController {
   private final ServerSecretParams serverSecretParams;
   private final SpamChecker spamChecker;
   private final MessageMetrics messageMetrics;
+  private final MessageDeliveryLoopMonitor messageDeliveryLoopMonitor;
   private final Clock clock;
 
   private static final int MAX_FETCH_ACCOUNT_CONCURRENCY = 8;
@@ -230,6 +232,7 @@ public class MessageController {
       final ServerSecretParams serverSecretParams,
       final SpamChecker spamChecker,
       final MessageMetrics messageMetrics,
+      final MessageDeliveryLoopMonitor messageDeliveryLoopMonitor,
       final Clock clock) {
     this.rateLimiters = rateLimiters;
     this.messageByteLimitEstimator = messageByteLimitEstimator;
@@ -248,6 +251,7 @@ public class MessageController {
     this.serverSecretParams = serverSecretParams;
     this.spamChecker = spamChecker;
     this.messageMetrics = messageMetrics;
+    this.messageDeliveryLoopMonitor = messageDeliveryLoopMonitor;
     this.clock = clock;
   }
 
@@ -785,6 +789,14 @@ public class MessageController {
           Metrics.summary(OUTGOING_MESSAGE_LIST_SIZE_BYTES_DISTRIBUTION_NAME, Tags.of(UserAgentTagUtil.getPlatformTag(userAgent)))
               .record(estimateMessageListSizeBytes(messages));
 
+          if (!messages.messages().isEmpty()) {
+            messageDeliveryLoopMonitor.recordDeliveryAttempt(auth.getAccount().getIdentifier(IdentityType.ACI),
+                auth.getAuthenticatedDevice().getId(),
+                messages.messages().getFirst().guid(),
+                userAgent,
+                "rest");
+          }
+
           if (messagesAndHasMore.second()) {
             pushNotificationScheduler.scheduleDelayedNotification(auth.getAccount(), auth.getAuthenticatedDevice(), NOTIFY_FOR_REMAINING_MESSAGES_DELAY);
           }
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/limits/MessageDeliveryLoopMonitor.java b/service/src/main/java/org/whispersystems/textsecuregcm/limits/MessageDeliveryLoopMonitor.java
new file mode 100644
index 000000000..77b4b80f1
--- /dev/null
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/limits/MessageDeliveryLoopMonitor.java
@@ -0,0 +1,72 @@
+package org.whispersystems.textsecuregcm.limits;
+
+import com.google.common.annotations.VisibleForTesting;
+import io.lettuce.core.ScriptOutputType;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.time.Duration;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.whispersystems.textsecuregcm.redis.ClusterLuaScript;
+import org.whispersystems.textsecuregcm.redis.FaultTolerantRedisCluster;
+
+public class MessageDeliveryLoopMonitor {
+
+  private final ClusterLuaScript getDeliveryAttemptsScript;
+
+  private static final Duration DELIVERY_ATTEMPTS_COUNTER_TTL = Duration.ofHours(1);
+  private static final int DELIVERY_LOOP_THRESHOLD = 5;
+
+  private static final Logger logger = LoggerFactory.getLogger(MessageDeliveryLoopMonitor.class);
+
+  public MessageDeliveryLoopMonitor(final FaultTolerantRedisCluster rateLimitCluster) {
+    try {
+      getDeliveryAttemptsScript =
+          ClusterLuaScript.fromResource(rateLimitCluster, "lua/get_delivery_attempt_count.lua", ScriptOutputType.INTEGER);
+    } catch (final IOException e) {
+      throw new UncheckedIOException("Failed to load 'get delivery attempt count' script", e);
+    }
+  }
+
+  /**
+   * Records an attempt to deliver a message with the given GUID to the given account/device pair and returns the number
+   * of consecutive attempts to deliver the same message and logs a warning if the message appears to be in a delivery
+   * loop. This method is intended to detect cases where a message remains at the head of a device's queue after
+   * repeated attempts to deliver the message, and so the given message GUID should be the first message of a "page"
+   * sent to clients.
+   *
+   * @param accountIdentifier the identifier of the destination account
+   * @param deviceId the destination device's ID within the given account
+   * @param messageGuid the GUID of the message
+   * @param userAgent the User-Agent header supplied by the caller
+   * @param context a human-readable string identifying the mechanism of message delivery (e.g. "rest" or "websocket")
+   */
+  public void recordDeliveryAttempt(final UUID accountIdentifier,
+      final byte deviceId,
+      final UUID messageGuid,
+      final String userAgent,
+      final String context) {
+
+    incrementDeliveryAttemptCount(accountIdentifier, deviceId, messageGuid)
+        .thenAccept(deliveryAttemptCount -> {
+          if (deliveryAttemptCount == DELIVERY_LOOP_THRESHOLD) {
+            logger.warn("Detected loop delivering message {} via {} to {}:{} ({})",
+                messageGuid, accountIdentifier, deviceId, context, userAgent);
+          }
+        });
+  }
+
+  @VisibleForTesting
+  CompletableFuture<Long> incrementDeliveryAttemptCount(final UUID accountIdentifier, final byte deviceId, final UUID messageGuid) {
+    final String firstMessageGuidKey = "firstMessageGuid::{" + accountIdentifier + ":" + deviceId + "}";
+    final String deliveryAttemptsKey = "firstMessageDeliveryAttempts::{" + accountIdentifier + ":" + deviceId + "}";
+
+    return getDeliveryAttemptsScript.executeAsync(
+            List.of(firstMessageGuidKey, deliveryAttemptsKey),
+            List.of(messageGuid.toString(), String.valueOf(DELIVERY_ATTEMPTS_COUNTER_TTL.toSeconds())))
+        .thenApply(result -> (long) result);
+  }
+}
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/websocket/AuthenticatedConnectListener.java b/service/src/main/java/org/whispersystems/textsecuregcm/websocket/AuthenticatedConnectListener.java
index 877142bff..9b7356d98 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/websocket/AuthenticatedConnectListener.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/websocket/AuthenticatedConnectListener.java
@@ -20,6 +20,7 @@ import java.util.concurrent.atomic.AtomicReference;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.auth.AuthenticatedDevice;
+import org.whispersystems.textsecuregcm.limits.MessageDeliveryLoopMonitor;
 import org.whispersystems.textsecuregcm.metrics.MessageMetrics;
 import org.whispersystems.textsecuregcm.metrics.UserAgentTagUtil;
 import org.whispersystems.textsecuregcm.push.ClientPresenceManager;
@@ -58,6 +59,7 @@ public class AuthenticatedConnectListener implements WebSocketConnectListener {
   private final ScheduledExecutorService scheduledExecutorService;
   private final Scheduler messageDeliveryScheduler;
   private final ClientReleaseManager clientReleaseManager;
+  private final MessageDeliveryLoopMonitor messageDeliveryLoopMonitor;
 
   private final Map<ClientPlatform, AtomicInteger> openAuthenticatedWebsocketsByClientPlatform;
   private final Map<ClientPlatform, AtomicInteger> openUnauthenticatedWebsocketsByClientPlatform;
@@ -77,7 +79,8 @@ public class AuthenticatedConnectListener implements WebSocketConnectListener {
       ClientPresenceManager clientPresenceManager,
       ScheduledExecutorService scheduledExecutorService,
       Scheduler messageDeliveryScheduler,
-      ClientReleaseManager clientReleaseManager) {
+      ClientReleaseManager clientReleaseManager,
+      MessageDeliveryLoopMonitor messageDeliveryLoopMonitor) {
     this.receiptSender = receiptSender;
     this.messagesManager = messagesManager;
     this.messageMetrics = messageMetrics;
@@ -87,6 +90,7 @@ public class AuthenticatedConnectListener implements WebSocketConnectListener {
     this.scheduledExecutorService = scheduledExecutorService;
     this.messageDeliveryScheduler = messageDeliveryScheduler;
     this.clientReleaseManager = clientReleaseManager;
+    this.messageDeliveryLoopMonitor = messageDeliveryLoopMonitor;
 
     openAuthenticatedWebsocketsByClientPlatform = new EnumMap<>(ClientPlatform.class);
     openUnauthenticatedWebsocketsByClientPlatform = new EnumMap<>(ClientPlatform.class);
@@ -151,7 +155,8 @@ public class AuthenticatedConnectListener implements WebSocketConnectListener {
           context.getClient(),
           scheduledExecutorService,
           messageDeliveryScheduler,
-          clientReleaseManager);
+          clientReleaseManager,
+          messageDeliveryLoopMonitor);
 
       openWebsocketAtomicInteger.incrementAndGet();
 
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 83ed82e6d..2334f24d9 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnection.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnection.java
@@ -39,7 +39,9 @@ import org.whispersystems.textsecuregcm.auth.AuthenticatedDevice;
 import org.whispersystems.textsecuregcm.controllers.MessageController;
 import org.whispersystems.textsecuregcm.entities.MessageProtos.Envelope;
 import org.whispersystems.textsecuregcm.identity.AciServiceIdentifier;
+import org.whispersystems.textsecuregcm.identity.IdentityType;
 import org.whispersystems.textsecuregcm.identity.ServiceIdentifier;
+import org.whispersystems.textsecuregcm.limits.MessageDeliveryLoopMonitor;
 import org.whispersystems.textsecuregcm.metrics.MessageMetrics;
 import org.whispersystems.textsecuregcm.metrics.MetricsUtil;
 import org.whispersystems.textsecuregcm.metrics.UserAgentTagUtil;
@@ -117,6 +119,7 @@ public class WebSocketConnection implements MessageAvailabilityListener, Displac
   private final MessageMetrics messageMetrics;
   private final PushNotificationManager pushNotificationManager;
   private final PushNotificationScheduler pushNotificationScheduler;
+  private final MessageDeliveryLoopMonitor messageDeliveryLoopMonitor;
 
   private final AuthenticatedDevice auth;
   private final WebSocketClient client;
@@ -155,7 +158,8 @@ public class WebSocketConnection implements MessageAvailabilityListener, Displac
       WebSocketClient client,
       ScheduledExecutorService scheduledExecutorService,
       Scheduler messageDeliveryScheduler,
-      ClientReleaseManager clientReleaseManager) {
+      ClientReleaseManager clientReleaseManager,
+      MessageDeliveryLoopMonitor messageDeliveryLoopMonitor) {
 
     this(receiptSender,
         messagesManager,
@@ -167,7 +171,8 @@ public class WebSocketConnection implements MessageAvailabilityListener, Displac
         DEFAULT_SEND_FUTURES_TIMEOUT_MILLIS,
         scheduledExecutorService,
         messageDeliveryScheduler,
-        clientReleaseManager);
+        clientReleaseManager,
+        messageDeliveryLoopMonitor);
   }
 
   @VisibleForTesting
@@ -181,7 +186,8 @@ public class WebSocketConnection implements MessageAvailabilityListener, Displac
       int sendFuturesTimeoutMillis,
       ScheduledExecutorService scheduledExecutorService,
       Scheduler messageDeliveryScheduler,
-      ClientReleaseManager clientReleaseManager) {
+      ClientReleaseManager clientReleaseManager,
+      MessageDeliveryLoopMonitor messageDeliveryLoopMonitor) {
 
     this.receiptSender = receiptSender;
     this.messagesManager = messagesManager;
@@ -194,6 +200,7 @@ public class WebSocketConnection implements MessageAvailabilityListener, Displac
     this.scheduledExecutorService = scheduledExecutorService;
     this.messageDeliveryScheduler = messageDeliveryScheduler;
     this.clientReleaseManager = clientReleaseManager;
+    this.messageDeliveryLoopMonitor = messageDeliveryLoopMonitor;
   }
 
   public void start() {
@@ -378,12 +385,22 @@ public class WebSocketConnection implements MessageAvailabilityListener, Displac
     final Publisher<Envelope> messages =
         messagesManager.getMessagesForDeviceReactive(auth.getAccount().getUuid(), auth.getAuthenticatedDevice(), cachedMessagesOnly);
 
+    final AtomicBoolean hasSentFirstMessage = new AtomicBoolean();
     final AtomicBoolean hasErrored = new AtomicBoolean();
 
     final Disposable subscription = Flux.from(messages)
         .name(SEND_MESSAGES_FLUX_NAME)
         .tap(Micrometer.metrics(Metrics.globalRegistry))
         .limitRate(MESSAGE_PUBLISHER_LIMIT_RATE)
+        .doOnNext(envelope -> {
+          if (hasSentFirstMessage.compareAndSet(false, true)) {
+            messageDeliveryLoopMonitor.recordDeliveryAttempt(auth.getAccount().getIdentifier(IdentityType.ACI),
+                auth.getAuthenticatedDevice().getId(),
+                UUID.fromString(envelope.getServerGuid()),
+                client.getUserAgent(),
+                "websocket");
+          }
+        })
         .flatMapSequential(envelope ->
             Mono.fromFuture(() -> sendMessage(envelope)
                     .orTimeout(sendFuturesTimeoutMillis, TimeUnit.MILLISECONDS))
diff --git a/service/src/main/resources/lua/get_delivery_attempt_count.lua b/service/src/main/resources/lua/get_delivery_attempt_count.lua
new file mode 100644
index 000000000..beba67e4f
--- /dev/null
+++ b/service/src/main/resources/lua/get_delivery_attempt_count.lua
@@ -0,0 +1,13 @@
+local firstMessageGuidKey = KEYS[1]
+local firstMessageAttemptsKey = KEYS[2]
+
+local firstMessageGuid = ARGV[1]
+local ttlSeconds = ARGV[2]
+
+if firstMessageGuid ~= redis.call("GET", firstMessageGuidKey) then
+    -- This is the first time we've attempted to deliver this message as the first message in a "page"
+    redis.call("SET", firstMessageGuidKey, firstMessageGuid, "EX", ttlSeconds)
+    redis.call("SET", firstMessageAttemptsKey, 0, "EX", ttlSeconds)
+end
+
+return redis.call("INCR", firstMessageAttemptsKey)
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/controllers/MessageControllerTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/controllers/MessageControllerTest.java
index 3339a7fd3..e4f0ce911 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/controllers/MessageControllerTest.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/controllers/MessageControllerTest.java
@@ -103,6 +103,7 @@ import org.whispersystems.textsecuregcm.identity.AciServiceIdentifier;
 import org.whispersystems.textsecuregcm.identity.PniServiceIdentifier;
 import org.whispersystems.textsecuregcm.identity.ServiceIdentifier;
 import org.whispersystems.textsecuregcm.limits.CardinalityEstimator;
+import org.whispersystems.textsecuregcm.limits.MessageDeliveryLoopMonitor;
 import org.whispersystems.textsecuregcm.limits.RateLimiter;
 import org.whispersystems.textsecuregcm.limits.RateLimiters;
 import org.whispersystems.textsecuregcm.mappers.RateLimitExceededExceptionMapper;
@@ -205,7 +206,8 @@ class MessageControllerTest {
           new MessageController(rateLimiters, cardinalityEstimator, messageSender, receiptSender, accountsManager,
               messagesManager, pushNotificationManager, pushNotificationScheduler, reportMessageManager, multiRecipientMessageExecutor,
               messageDeliveryScheduler, ReportSpamTokenProvider.noop(), mock(ClientReleaseManager.class), dynamicConfigurationManager,
-              serverSecretParams, SpamChecker.noop(), new MessageMetrics(), clock))
+              serverSecretParams, SpamChecker.noop(), new MessageMetrics(), mock(MessageDeliveryLoopMonitor.class),
+              clock))
       .build();
 
   @BeforeEach
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/limits/MessageDeliveryLoopMonitorTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/limits/MessageDeliveryLoopMonitorTest.java
new file mode 100644
index 000000000..a4c09fb01
--- /dev/null
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/limits/MessageDeliveryLoopMonitorTest.java
@@ -0,0 +1,38 @@
+package org.whispersystems.textsecuregcm.limits;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.UUID;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.whispersystems.textsecuregcm.redis.RedisClusterExtension;
+import org.whispersystems.textsecuregcm.storage.Device;
+
+class MessageDeliveryLoopMonitorTest {
+
+  private MessageDeliveryLoopMonitor messageDeliveryLoopMonitor;
+
+  @RegisterExtension
+  static final RedisClusterExtension REDIS_CLUSTER_EXTENSION = RedisClusterExtension.builder().build();
+
+  @BeforeEach
+  void setUp() {
+    messageDeliveryLoopMonitor = new MessageDeliveryLoopMonitor(REDIS_CLUSTER_EXTENSION.getRedisCluster());
+  }
+
+  @Test
+  void incrementDeliveryAttemptCount() {
+    final UUID accountIdentifier = UUID.randomUUID();
+    final byte deviceId = Device.PRIMARY_ID;
+
+    assertEquals(1, messageDeliveryLoopMonitor.incrementDeliveryAttemptCount(accountIdentifier, deviceId, UUID.randomUUID()).join());
+    assertEquals(1, messageDeliveryLoopMonitor.incrementDeliveryAttemptCount(accountIdentifier, deviceId, UUID.randomUUID()).join());
+
+    final UUID repeatedDeliveryGuid = UUID.randomUUID();
+
+    for (int i = 1; i < 10; i++) {
+      assertEquals(i, messageDeliveryLoopMonitor.incrementDeliveryAttemptCount(accountIdentifier, deviceId, repeatedDeliveryGuid).join());
+    }
+  }
+}
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 53622c21e..e9d0863d6 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionIntegrationTest.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionIntegrationTest.java
@@ -46,6 +46,7 @@ import org.mockito.stubbing.Answer;
 import org.whispersystems.textsecuregcm.auth.AuthenticatedDevice;
 import org.whispersystems.textsecuregcm.entities.MessageProtos;
 import org.whispersystems.textsecuregcm.entities.MessageProtos.Envelope;
+import org.whispersystems.textsecuregcm.limits.MessageDeliveryLoopMonitor;
 import org.whispersystems.textsecuregcm.metrics.MessageMetrics;
 import org.whispersystems.textsecuregcm.push.PushNotificationManager;
 import org.whispersystems.textsecuregcm.push.PushNotificationScheduler;
@@ -133,7 +134,8 @@ class WebSocketConnectionIntegrationTest {
         webSocketClient,
         scheduledExecutorService,
         messageDeliveryScheduler,
-        clientReleaseManager);
+        clientReleaseManager,
+        mock(MessageDeliveryLoopMonitor.class));
 
     final List<MessageProtos.Envelope> expectedMessages = new ArrayList<>(persistedMessageCount + cachedMessageCount);
 
@@ -220,7 +222,8 @@ class WebSocketConnectionIntegrationTest {
         webSocketClient,
         scheduledExecutorService,
         messageDeliveryScheduler,
-        clientReleaseManager);
+        clientReleaseManager,
+        mock(MessageDeliveryLoopMonitor.class));
 
     final int persistedMessageCount = 207;
     final int cachedMessageCount = 173;
@@ -289,7 +292,8 @@ class WebSocketConnectionIntegrationTest {
         100, // use a very short timeout, so that this test completes quickly
         scheduledExecutorService,
         messageDeliveryScheduler,
-        clientReleaseManager);
+        clientReleaseManager,
+        mock(MessageDeliveryLoopMonitor.class));
 
     final int persistedMessageCount = 207;
     final int cachedMessageCount = 173;
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionTest.java
index 0a114c051..9c4346686 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionTest.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnectionTest.java
@@ -56,6 +56,7 @@ import org.mockito.stubbing.Answer;
 import org.whispersystems.textsecuregcm.auth.AccountAuthenticator;
 import org.whispersystems.textsecuregcm.auth.AuthenticatedDevice;
 import org.whispersystems.textsecuregcm.identity.AciServiceIdentifier;
+import org.whispersystems.textsecuregcm.limits.MessageDeliveryLoopMonitor;
 import org.whispersystems.textsecuregcm.metrics.MessageMetrics;
 import org.whispersystems.textsecuregcm.push.ClientPresenceManager;
 import org.whispersystems.textsecuregcm.push.PushNotificationManager;
@@ -124,7 +125,8 @@ class WebSocketConnectionTest {
         new WebSocketAccountAuthenticator(accountAuthenticator, mock(PrincipalSupplier.class));
     AuthenticatedConnectListener connectListener = new AuthenticatedConnectListener(receiptSender, messagesManager,
         new MessageMetrics(), mock(PushNotificationManager.class), mock(PushNotificationScheduler.class),
-        mock(ClientPresenceManager.class), retrySchedulingExecutor, messageDeliveryScheduler, clientReleaseManager);
+        mock(ClientPresenceManager.class), retrySchedulingExecutor, messageDeliveryScheduler, clientReleaseManager,
+        mock(MessageDeliveryLoopMonitor.class));
     WebSocketSessionContext sessionContext = mock(WebSocketSessionContext.class);
 
     when(accountAuthenticator.authenticate(eq(new BasicCredentials(VALID_USER, VALID_PASSWORD))))
@@ -628,7 +630,7 @@ class WebSocketConnectionTest {
   private @NotNull WebSocketConnection webSocketConnection(final WebSocketClient client) {
     return new WebSocketConnection(receiptSender, messagesManager, new MessageMetrics(),
         mock(PushNotificationManager.class), mock(PushNotificationScheduler.class), auth, client,
-        retrySchedulingExecutor, Schedulers.immediate(), clientReleaseManager);
+        retrySchedulingExecutor, Schedulers.immediate(), clientReleaseManager, mock(MessageDeliveryLoopMonitor.class));
   }
 
   @Test