diff --git a/SignalServiceKit/src/Devices/OWSReadReceiptsForSenderMessage.m b/SignalServiceKit/src/Devices/OWSReadReceiptsForSenderMessage.m
index 2542a185f..3fc3ad602 100644
--- a/SignalServiceKit/src/Devices/OWSReadReceiptsForSenderMessage.m
+++ b/SignalServiceKit/src/Devices/OWSReadReceiptsForSenderMessage.m
@@ -36,6 +36,13 @@ NS_ASSUME_NONNULL_BEGIN
     return NO;
 }
 
+- (BOOL)isSilent
+{
+    // Avoid "phantom messages" for "recipient read receipts".
+
+    return YES;
+}
+
 - (NSData *)buildPlainTextData:(SignalRecipient *)recipient
 {
     OWSAssert(recipient);
diff --git a/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.h b/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.h
index 82aeb7a01..e8920ad21 100644
--- a/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.h
+++ b/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.h
@@ -110,6 +110,8 @@ typedef NS_ENUM(NSInteger, TSGroupMetaMessage) {
 // Map of "recipient id"-to-"read time" of the recipients who have read the message.
 @property (atomic, readonly) NSDictionary<NSString *, NSNumber *> *recipientReadMap;
 
+@property (nonatomic, readonly) BOOL isSilent;
+
 /**
  * Signal Identifier (e.g. e164 number) or nil if in a group thread.
  */
diff --git a/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m b/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m
index 2e038eb2b..28b00cfc6 100644
--- a/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m
+++ b/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m
@@ -228,6 +228,11 @@ NSString *const kTSOutgoingMessageSentRecipientAll = @"kTSOutgoingMessageSentRec
     }
 }
 
+- (BOOL)isSilent
+{
+    return NO;
+}
+
 #pragma mark - Update Methods
 
 // This method does the work for the "updateWith..." methods.  Please see
diff --git a/SignalServiceKit/src/Messages/OWSMessageSender.m b/SignalServiceKit/src/Messages/OWSMessageSender.m
index d8c944cef..d9bcec134 100644
--- a/SignalServiceKit/src/Messages/OWSMessageSender.m
+++ b/SignalServiceKit/src/Messages/OWSMessageSender.m
@@ -879,7 +879,7 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
 
     NSArray<NSDictionary *> *deviceMessages;
     @try {
-        deviceMessages = [self deviceMessages:message forRecipient:recipient inThread:thread];
+        deviceMessages = [self deviceMessages:message forRecipient:recipient];
     } @catch (NSException *exception) {
         deviceMessages = @[];
         if ([exception.name isEqualToString:UntrustedIdentityKeyException]) {
@@ -1173,8 +1173,10 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
 
 - (NSArray<NSDictionary *> *)deviceMessages:(TSOutgoingMessage *)message
                                forRecipient:(SignalRecipient *)recipient
-                                   inThread:(TSThread *)thread
 {
+    OWSAssert(message);
+    OWSAssert(recipient);
+
     NSMutableArray *messagesArray = [NSMutableArray arrayWithCapacity:recipient.devices.count];
 
     NSData *plainText = [message buildPlainTextData:recipient];
@@ -1191,7 +1193,8 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
                     messageDict = [self encryptedMessageWithPlaintext:plainText
                                                           toRecipient:recipient.uniqueId
                                                              deviceId:deviceNumber
-                                                        keyingStorage:[TSStorageManager sharedManager]];
+                                                        keyingStorage:self.storageManager
+                                                             isSilent:message.isSilent];
                 } @catch (NSException *exception) {
                     encryptionException = exception;
                 }
@@ -1225,7 +1228,13 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
                                     toRecipient:(NSString *)identifier
                                        deviceId:(NSNumber *)deviceNumber
                                   keyingStorage:(TSStorageManager *)storage
+                                       isSilent:(BOOL)isSilent
 {
+    OWSAssert(plainText);
+    OWSAssert(identifier.length > 0);
+    OWSAssert(deviceNumber);
+    OWSAssert(storage);
+
     if (![storage containsSession:identifier deviceId:[deviceNumber intValue]]) {
         __block dispatch_semaphore_t sema = dispatch_semaphore_create(0);
         __block PreKeyBundle *_Nullable bundle;
@@ -1305,6 +1314,7 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
                                                                                recipientId:identifier
                                                                                     device:[deviceNumber intValue]
                                                                                    content:serializedMessage
+                                                                                  isSilent:isSilent
                                                                             registrationId:cipher.remoteRegistrationId];
 
     NSError *error;
diff --git a/SignalServiceKit/src/Messages/OWSMessageServiceParams.h b/SignalServiceKit/src/Messages/OWSMessageServiceParams.h
index 796dbfe78..3cb01e29c 100644
--- a/SignalServiceKit/src/Messages/OWSMessageServiceParams.h
+++ b/SignalServiceKit/src/Messages/OWSMessageServiceParams.h
@@ -1,5 +1,6 @@
-//  Created by Frederic Jacobs on 18/11/14.
-//  Copyright (c) 2014 Open Whisper Systems. All rights reserved.
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
 
 #import "TSConstants.h"
 #import <Mantle/Mantle.h>
@@ -7,6 +8,9 @@
 /**
  * Contstructs the per-device-message parameters used when submitting a message to
  * the Signal Web Service.
+ *
+ * See:
+ * https://github.com/WhisperSystems/libsignal-service-java/blob/master/java/src/main/java/org/whispersystems/signalservice/internal/push/OutgoingPushMessage.java
  */
 @interface OWSMessageServiceParams : MTLModel <MTLJSONSerializing>
 
@@ -15,11 +19,13 @@
 @property (nonatomic, readonly) int destinationDeviceId;
 @property (nonatomic, readonly) int destinationRegistrationId;
 @property (nonatomic, readonly) NSString *content;
+@property (nonatomic, readonly) BOOL silent;
 
 - (instancetype)initWithType:(TSWhisperMessageType)type
                  recipientId:(NSString *)destination
                       device:(int)deviceId
                      content:(NSData *)content
+                    isSilent:(BOOL)isSilent
               registrationId:(int)registrationId;
 
 @end
diff --git a/SignalServiceKit/src/Messages/OWSMessageServiceParams.m b/SignalServiceKit/src/Messages/OWSMessageServiceParams.m
index cf0df0df4..bf7665186 100644
--- a/SignalServiceKit/src/Messages/OWSMessageServiceParams.m
+++ b/SignalServiceKit/src/Messages/OWSMessageServiceParams.m
@@ -1,5 +1,6 @@
-//  Created by Frederic Jacobs on 18/11/14.
-//  Copyright (c) 2014 Open Whisper Systems. All rights reserved.
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
 
 #import "OWSMessageServiceParams.h"
 #import "NSData+Base64.h"
@@ -16,6 +17,7 @@
                  recipientId:(NSString *)destination
                       device:(int)deviceId
                      content:(NSData *)content
+                    isSilent:(BOOL)isSilent
               registrationId:(int)registrationId
 {
     self = [super init];
@@ -29,6 +31,7 @@
     _destinationDeviceId = deviceId;
     _destinationRegistrationId = registrationId;
     _content = [content base64EncodedString];
+    _silent = isSilent;
 
     return self;
 }
diff --git a/SignalServiceKit/src/Messages/OWSOutgoingCallMessage.m b/SignalServiceKit/src/Messages/OWSOutgoingCallMessage.m
index 5ab30469c..597f77b8b 100644
--- a/SignalServiceKit/src/Messages/OWSOutgoingCallMessage.m
+++ b/SignalServiceKit/src/Messages/OWSOutgoingCallMessage.m
@@ -112,6 +112,13 @@ NS_ASSUME_NONNULL_BEGIN
     return NO;
 }
 
+- (BOOL)isSilent
+{
+    // Avoid "phantom messages" for "outgoing call messages".
+
+    return YES;
+}
+
 //
 ///**
 // * override thread accessor in superclass, since this model is never saved.