diff --git a/Signal/src/Jobs/MessageFetcherJob.swift b/Signal/src/Jobs/MessageFetcherJob.swift
index a6ab01294..6fd5c4e92 100644
--- a/Signal/src/Jobs/MessageFetcherJob.swift
+++ b/Signal/src/Jobs/MessageFetcherJob.swift
@@ -198,8 +198,8 @@ private
 
     private func acknowledgeDelivery(envelope: SSKProtoEnvelope) {
         let request: TSRequest
-        if let serverGuid = envelope.serverGuid, envelope.hasServerTimestamp, serverGuid.count > 0, envelope.serverTimestamp > 0 {
-            request = OWSRequestFactory.acknowledgeMessageDeliveryRequest(withServerGuid: serverGuid, serverTimestamp: envelope.serverTimestamp)
+        if let serverGuid = envelope.serverGuid, serverGuid.count > 0 {
+            request = OWSRequestFactory.acknowledgeMessageDeliveryRequest(withServerGuid: serverGuid)
         } else if let source = envelope.source, source.count > 0, envelope.timestamp > 0 {
             request = OWSRequestFactory.acknowledgeMessageDeliveryRequest(withSource: source, timestamp: envelope.timestamp)
         } else {
diff --git a/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.h b/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.h
index 9a0d13abe..490403435 100644
--- a/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.h
+++ b/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.h
@@ -23,8 +23,7 @@ typedef NS_ENUM(NSUInteger, TSVerificationTransport) { TSVerificationTransportVo
 
 + (TSRequest *)acknowledgeMessageDeliveryRequestWithSource:(NSString *)source timestamp:(UInt64)timestamp;
 
-+ (TSRequest *)acknowledgeMessageDeliveryRequestWithServerGuid:(NSString *)serverGuid
-                                               serverTimestamp:(UInt64)serverTimestamp;
++ (TSRequest *)acknowledgeMessageDeliveryRequestWithServerGuid:(NSString *)serverGuid;
 
 + (TSRequest *)deleteDeviceRequestWithDevice:(OWSDevice *)device;
 
diff --git a/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.m b/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.m
index 2ef8041dc..bad2dae92 100644
--- a/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.m
+++ b/SignalServiceKit/src/Network/API/Requests/OWSRequestFactory.m
@@ -73,12 +73,10 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 + (TSRequest *)acknowledgeMessageDeliveryRequestWithServerGuid:(NSString *)serverGuid
-                                               serverTimestamp:(UInt64)serverTimestamp
 {
     OWSAssertDebug(serverGuid.length > 0);
-    OWSAssertDebug(serverTimestamp > 0);
 
-    NSString *path = [NSString stringWithFormat:@"v1/messages/%@/%llu", serverGuid, serverTimestamp];
+    NSString *path = [NSString stringWithFormat:@"v1/messages/uuid/%@", serverGuid];
 
     return [TSRequest requestWithUrl:[NSURL URLWithString:path] method:@"DELETE" parameters:@{}];
 }