diff --git a/SignalServiceKit/src/Devices/OWSDevice.h b/SignalServiceKit/src/Devices/OWSDevice.h
index 90bdfb65c..e642f744d 100644
--- a/SignalServiceKit/src/Devices/OWSDevice.h
+++ b/SignalServiceKit/src/Devices/OWSDevice.h
@@ -43,7 +43,7 @@ extern uint32_t const OWSDevicePrimaryDeviceId;
  * This will create missing devices, update existing devices, and delete stale devices.
  * @param devices Removes any existing devices, replacing them with `devices`
  *
- * Returns YET if any devices were added or removed.
+ * Returns YES if any devices were added or removed.
  */
 + (BOOL)replaceAll:(NSArray<OWSDevice *> *)devices;
 
diff --git a/SignalServiceKit/src/Messages/OWSMessageSender.m b/SignalServiceKit/src/Messages/OWSMessageSender.m
index c7edf9682..5c5e7d999 100644
--- a/SignalServiceKit/src/Messages/OWSMessageSender.m
+++ b/SignalServiceKit/src/Messages/OWSMessageSender.m
@@ -933,6 +933,9 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
     // Consume an attempt.
     messageSend.remainingAttempts = messageSend.remainingAttempts - 1;
 
+    // We need to disable UD for sync messages before we build the device messages,
+    // since we don't want to build a device message for the local device in the
+    // non-UD auth case.
     if ([message isKindOfClass:[OWSOutgoingSyncMessage class]]
         && ![message isKindOfClass:[OWSOutgoingSentMessageTranscript class]]) {
         [messageSend disableUD];