diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
index 0aafdd920..d8df0518c 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
@@ -2884,7 +2884,7 @@ typedef enum : NSUInteger {
 
     OWSAssert(type);
     OWSAssert(filename);
-    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithURL:url];
+    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithURL:url shouldDeleteOnDeallocation:NO];
     if (!dataSource) {
         OWSFail(@"%@ attachment data was unexpectedly empty for picked document url: %@", self.logTag, url);
 
@@ -3176,14 +3176,6 @@ typedef enum : NSUInteger {
         }];
 }
 
-- (NSURL *)videoTempFolder
-{
-    NSString *temporaryDirectory = NSTemporaryDirectory();
-    NSString *videoDirPath = [temporaryDirectory stringByAppendingPathComponent:@"videos"];
-    [OWSFileSystem ensureDirectoryExists:videoDirPath];
-    return [NSURL fileURLWithPath:videoDirPath];
-}
-
 - (void)sendQualityAdjustedAttachmentForVideo:(NSURL *)movieURL
                                      filename:(NSString *)filename
                            skipApprovalDialog:(BOOL)skipApprovalDialog
@@ -3194,7 +3186,8 @@ typedef enum : NSUInteger {
         presentFromViewController:self
                         canCancel:YES
                   backgroundBlock:^(ModalActivityIndicatorViewController *modalActivityIndicator) {
-                      DataSource *dataSource = [DataSourcePath dataSourceWithURL:movieURL];
+                      DataSource *dataSource =
+                          [DataSourcePath dataSourceWithURL:movieURL shouldDeleteOnDeallocation:NO];
                       dataSource.sourceFilename = filename;
                       VideoCompressionResult *compressionResult =
                           [SignalAttachment compressVideoAsMp4WithDataSource:dataSource
@@ -3675,7 +3668,8 @@ typedef enum : NSUInteger {
         return;
     }
 
-    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithURL:self.audioRecorder.url];
+    DataSource *_Nullable dataSource =
+        [DataSourcePath dataSourceWithURL:self.audioRecorder.url shouldDeleteOnDeallocation:YES];
     self.audioRecorder = nil;
 
     if (!dataSource) {
@@ -3687,8 +3681,6 @@ typedef enum : NSUInteger {
     NSString *filename = [NSLocalizedString(@"VOICE_MESSAGE_FILE_NAME", @"Filename for voice messages.")
         stringByAppendingPathExtension:@"m4a"];
     [dataSource setSourceFilename:filename];
-    // Remove temporary file when complete.
-    [dataSource setShouldDeleteOnDeallocation];
     SignalAttachment *attachment =
         [SignalAttachment voiceMessageAttachmentWithDataSource:dataSource dataUTI:(NSString *)kUTTypeMPEG4Audio];
     DDLogVerbose(@"%@ voice memo duration: %f, file size: %zd", self.logTag, durationSeconds, [dataSource dataLength]);
@@ -3948,9 +3940,8 @@ typedef enum : NSUInteger {
     if (newGroupModel.groupImage) {
         NSData *data = UIImagePNGRepresentation(newGroupModel.groupImage);
         DataSource *_Nullable dataSource = [DataSourceValue dataSourceWithData:data fileExtension:@"png"];
-        [self.messageSender enqueueAttachment:dataSource
+        [self.messageSender enqueueTemporaryAttachment:dataSource
             contentType:OWSMimeTypeImagePng
-            sourceFilename:nil
             inMessage:message
             success:^{
                 DDLogDebug(@"%@ Successfully sent group update with avatar", self.logTag);
diff --git a/Signal/src/ViewControllers/DebugUI/DebugUIMessages.m b/Signal/src/ViewControllers/DebugUI/DebugUIMessages.m
index d2609948c..7648b91c8 100644
--- a/Signal/src/ViewControllers/DebugUI/DebugUIMessages.m
+++ b/Signal/src/ViewControllers/DebugUI/DebugUIMessages.m
@@ -351,7 +351,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSMessageSender *messageSender = [Environment current].messageSender;
     NSString *filename = [filePath lastPathComponent];
     NSString *utiType = [MIMETypeUtil utiTypeForFileExtension:filename.pathExtension];
-    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath];
+    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath shouldDeleteOnDeallocation:NO];
     [dataSource setSourceFilename:filename];
     SignalAttachment *attachment =
         [SignalAttachment attachmentWithDataSource:dataSource dataUTI:utiType imageQuality:TSImageQualityOriginal];
@@ -1701,7 +1701,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     NSString *filename = [filePath lastPathComponent];
     NSString *utiType = [MIMETypeUtil utiTypeForFileExtension:filename.pathExtension];
-    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath];
+    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath shouldDeleteOnDeallocation:NO];
     [dataSource setSourceFilename:filename];
     SignalAttachment *attachment =
         [SignalAttachment attachmentWithDataSource:dataSource dataUTI:utiType imageQuality:TSImageQualityOriginal];
@@ -4593,7 +4593,8 @@ typedef OWSContact * (^OWSContactBlock)(YapDatabaseReadWriteTransaction *transac
     OWSAssert(transaction);
 
     if (isAttachmentDownloaded) {
-        DataSource *dataSource = [DataSourcePath dataSourceWithFilePath:fakeAssetLoader.filePath];
+        DataSource *dataSource =
+            [DataSourcePath dataSourceWithFilePath:fakeAssetLoader.filePath shouldDeleteOnDeallocation:NO];
         NSString *filename = dataSource.sourceFilename;
         // To support "fake missing" attachments, we sometimes lie about the
         // length of the data.
diff --git a/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m b/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m
index 1b3229e41..fb6f36c86 100644
--- a/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m
+++ b/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m
@@ -233,7 +233,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     OWSMessageSender *messageSender = [Environment current].messageSender;
     NSString *utiType = [MIMETypeUtil utiTypeForFileExtension:fileName.pathExtension];
-    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath];
+    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath shouldDeleteOnDeallocation:YES];
     [dataSource setSourceFilename:fileName];
     SignalAttachment *attachment = [SignalAttachment attachmentWithDataSource:dataSource dataUTI:utiType];
     NSData *databasePassword = [OWSPrimaryStorage.sharedManager databasePassword];
@@ -262,7 +262,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     OWSMessageSender *messageSender = [Environment current].messageSender;
     NSString *utiType = [MIMETypeUtil utiTypeForFileExtension:fileName.pathExtension];
-    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath];
+    DataSource *_Nullable dataSource = [DataSourcePath dataSourceWithFilePath:filePath shouldDeleteOnDeallocation:YES];
     [dataSource setSourceFilename:fileName];
     SignalAttachment *attachment = [SignalAttachment attachmentWithDataSource:dataSource dataUTI:utiType];
     if (!attachment || [attachment hasError]) {
diff --git a/Signal/src/ViewControllers/GifPicker/GifPickerViewController.swift b/Signal/src/ViewControllers/GifPicker/GifPickerViewController.swift
index 537fc9064..b4bbf8f4c 100644
--- a/Signal/src/ViewControllers/GifPicker/GifPickerViewController.swift
+++ b/Signal/src/ViewControllers/GifPicker/GifPickerViewController.swift
@@ -370,7 +370,8 @@ class GifPickerViewController: OWSViewController, UISearchBarDelegate, UICollect
             }
 
             let filePath = asset.filePath
-            guard let dataSource = DataSourcePath.dataSource(withFilePath: filePath) else {
+            guard let dataSource = DataSourcePath.dataSource(withFilePath: filePath,
+                shouldDeleteOnDeallocation: false) else {
                 owsFail("\(strongSelf.TAG) couldn't load asset.")
                 return
             }
diff --git a/Signal/src/ViewControllers/NewGroupViewController.m b/Signal/src/ViewControllers/NewGroupViewController.m
index 901ea951e..26d7681f4 100644
--- a/Signal/src/ViewControllers/NewGroupViewController.m
+++ b/Signal/src/ViewControllers/NewGroupViewController.m
@@ -490,12 +490,11 @@ const NSUInteger kNewGroupViewControllerAvatarWidth = 68;
                               NSData *data = UIImagePNGRepresentation(model.groupImage);
                               DataSource *_Nullable dataSource =
                                   [DataSourceValue dataSourceWithData:data fileExtension:@"png"];
-                              [self.messageSender enqueueAttachment:dataSource
-                                                        contentType:OWSMimeTypeImagePng
-                                                     sourceFilename:nil
-                                                          inMessage:message
-                                                            success:successHandler
-                                                            failure:failureHandler];
+                              [self.messageSender enqueueTemporaryAttachment:dataSource
+                                                                 contentType:OWSMimeTypeImagePng
+                                                                   inMessage:message
+                                                                     success:successHandler
+                                                                     failure:failureHandler];
                           } else {
                               [self.messageSender enqueueMessage:message success:successHandler failure:failureHandler];
                           }
diff --git a/SignalMessaging/attachments/SignalAttachment.swift b/SignalMessaging/attachments/SignalAttachment.swift
index 147b18ae2..1382e5385 100644
--- a/SignalMessaging/attachments/SignalAttachment.swift
+++ b/SignalMessaging/attachments/SignalAttachment.swift
@@ -980,7 +980,8 @@ public class SignalAttachment: NSObject {
             let baseFilename = dataSource.sourceFilename
             let mp4Filename = baseFilename?.filenameWithoutExtension.appendingFileExtension("mp4")
 
-            guard let dataSource = DataSourcePath.dataSource(with: exportURL) else {
+            guard let dataSource = DataSourcePath.dataSource(with: exportURL,
+                                                             shouldDeleteOnDeallocation: true) else {
                 owsFail("Failed to build data source for exported video URL")
                 let attachment = SignalAttachment(dataSource: DataSourceValue.emptyDataSource(), dataUTI: dataUTI)
                 attachment.error = .couldNotConvertToMpeg4
@@ -988,7 +989,6 @@ public class SignalAttachment: NSObject {
                 return
             }
 
-            dataSource.setShouldDeleteOnDeallocation()
             dataSource.sourceFilename = mp4Filename
 
             let attachment = SignalAttachment(dataSource: dataSource, dataUTI: kUTTypeMPEG4 as String)
diff --git a/SignalMessaging/contacts/OWSContactsSyncing.m b/SignalMessaging/contacts/OWSContactsSyncing.m
index f2285ab09..dbd5f4fd0 100644
--- a/SignalMessaging/contacts/OWSContactsSyncing.m
+++ b/SignalMessaging/contacts/OWSContactsSyncing.m
@@ -126,7 +126,7 @@ NSString *const kOWSPrimaryStorageOWSContactsSyncingLastMessageKey
 
         __block NSData *messageData;
         __block NSData *lastMessageData;
-        [self.editingDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *_Nonnull transaction) {
+        [self.editingDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
             messageData = [syncContactsMessage buildPlainTextAttachmentDataWithTransaction:transaction];
             lastMessageData = [transaction objectForKey:kOWSPrimaryStorageOWSContactsSyncingLastMessageKey
                                            inCollection:kOWSPrimaryStorageOWSContactsSyncingCollection];
diff --git a/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m b/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m
index 24259c7b7..8f1f96a06 100644
--- a/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m
+++ b/SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m
@@ -354,6 +354,41 @@ NSString *NSStringForOutgoingMessageRecipientState(OWSOutgoingMessageRecipientSt
     return self;
 }
 
+- (void)dealloc
+{
+    [self removeTemporaryAttachments];
+}
+
+// Each message has the responsibility for eagerly cleaning up its attachments.
+// Normally this is done in [TSMessage removeWithTransaction], but that doesn't
+// apply for "transient", unsaved messages (i.e. shouldBeSaved == NO).  These
+// messages should clean up their attachments upon deallocation.
+- (void)removeTemporaryAttachments
+{
+    if (self.shouldBeSaved) {
+        // Message is not transient; no need to clean up attachments.
+        return;
+    }
+    NSArray<NSString *> *_Nullable attachmentIds = self.attachmentIds;
+    if (attachmentIds.count < 1) {
+        return;
+    }
+    [self.dbReadWriteConnection asyncReadWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+        for (NSString *attachmentId in attachmentIds) {
+            // We need to fetch each attachment, since [TSAttachment removeWithTransaction:] does important work.
+            TSAttachment *_Nullable attachment =
+                [TSAttachment fetchObjectWithUniqueID:attachmentId transaction:transaction];
+            if (!attachment) {
+                OWSCFail(@"%@ couldn't load interaction's attachment for deletion.", TSOutgoingMessage.logTag);
+                continue;
+            }
+            [attachment removeWithTransaction:transaction];
+        };
+    }];
+}
+
+#pragma mark -
+
 - (TSOutgoingMessageState)messageState
 {
     TSOutgoingMessageState newMessageState =
diff --git a/SignalServiceKit/src/Messages/OWSMessageManager.m b/SignalServiceKit/src/Messages/OWSMessageManager.m
index 7becd7cf5..db16d84bd 100644
--- a/SignalServiceKit/src/Messages/OWSMessageManager.m
+++ b/SignalServiceKit/src/Messages/OWSMessageManager.m
@@ -825,9 +825,8 @@ NS_ASSUME_NONNULL_BEGIN
     if (gThread.groupModel.groupImage) {
         NSData *data = UIImagePNGRepresentation(gThread.groupModel.groupImage);
         DataSource *_Nullable dataSource = [DataSourceValue dataSourceWithData:data fileExtension:@"png"];
-        [self.messageSender enqueueAttachment:dataSource
+        [self.messageSender enqueueTemporaryAttachment:dataSource
             contentType:OWSMimeTypeImagePng
-            sourceFilename:nil
             inMessage:message
             success:^{
                 DDLogDebug(@"%@ Successfully sent group update with avatar", self.logTag);
diff --git a/SignalServiceKit/src/Util/DataSource.h b/SignalServiceKit/src/Util/DataSource.h
index c65d693c8..74ba0fc25 100755
--- a/SignalServiceKit/src/Util/DataSource.h
+++ b/SignalServiceKit/src/Util/DataSource.h
@@ -29,10 +29,6 @@ NS_ASSUME_NONNULL_BEGIN
 // Returns YES on success.
 - (BOOL)writeToPath:(NSString *)dstFilePath;
 
-// If called, this data source will try to delete its on-disk contents
-// when it is deallocated.
-- (void)setShouldDeleteOnDeallocation;
-
 - (BOOL)isValidImage;
 
 @end
@@ -57,9 +53,10 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface DataSourcePath : DataSource
 
-+ (nullable DataSource *)dataSourceWithURL:(NSURL *)fileUrl;
++ (nullable DataSource *)dataSourceWithURL:(NSURL *)fileUrl shouldDeleteOnDeallocation:(BOOL)shouldDeleteOnDeallocation;
 
-+ (nullable DataSource *)dataSourceWithFilePath:(NSString *)filePath;
++ (nullable DataSource *)dataSourceWithFilePath:(NSString *)filePath
+                     shouldDeleteOnDeallocation:(BOOL)shouldDeleteOnDeallocation;
 
 @end
 
diff --git a/SignalServiceKit/src/Util/DataSource.m b/SignalServiceKit/src/Util/DataSource.m
index df21acf9f..fcebd4511 100755
--- a/SignalServiceKit/src/Util/DataSource.m
+++ b/SignalServiceKit/src/Util/DataSource.m
@@ -60,11 +60,6 @@ NS_ASSUME_NONNULL_BEGIN
     return NO;
 }
 
-- (void)setShouldDeleteOnDeallocation
-{
-    self.shouldDeleteOnDeallocation = YES;
-}
-
 - (BOOL)isValidImage
 {
     NSString *_Nullable dataPath = [self dataPathIfOnDisk];
@@ -102,7 +97,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic) NSString *fileExtension;
 
 // This property is lazy-populated.
-@property (nonatomic) NSString *cachedFilePath;
+@property (nonatomic, nullable) NSString *cachedFilePath;
 
 @end
 
@@ -113,7 +108,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)dealloc
 {
     if (self.shouldDeleteOnDeallocation) {
-        NSString *filePath = self.cachedFilePath;
+        NSString *_Nullable filePath = self.cachedFilePath;
         if (filePath) {
             dispatch_async(dispatch_get_main_queue(), ^{
                 NSError *error;
@@ -126,7 +121,8 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
-+ (nullable DataSource *)dataSourceWithData:(NSData *)data fileExtension:(NSString *)fileExtension
++ (nullable DataSource *)dataSourceWithData:(NSData *)data
+                              fileExtension:(NSString *)fileExtension
 {
     OWSAssert(data);
 
@@ -137,12 +133,12 @@ NS_ASSUME_NONNULL_BEGIN
     DataSourceValue *instance = [DataSourceValue new];
     instance.dataValue = data;
     instance.fileExtension = fileExtension;
-    // Always try to clean up temp files created by this instance.
-    [instance setShouldDeleteOnDeallocation];
+    instance.shouldDeleteOnDeallocation = YES;
     return instance;
 }
 
-+ (nullable DataSource *)dataSourceWithData:(NSData *)data utiType:(NSString *)utiType
++ (nullable DataSource *)dataSourceWithData:(NSData *)data
+                                    utiType:(NSString *)utiType
 {
     NSString *fileExtension = [MIMETypeUtil fileExtensionForUTIType:utiType];
     return [self dataSourceWithData:data fileExtension:fileExtension];
@@ -269,7 +265,7 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
-+ (nullable DataSource *)dataSourceWithURL:(NSURL *)fileUrl
++ (nullable DataSource *)dataSourceWithURL:(NSURL *)fileUrl shouldDeleteOnDeallocation:(BOOL)shouldDeleteOnDeallocation
 {
     OWSAssert(fileUrl);
 
@@ -278,10 +274,12 @@ NS_ASSUME_NONNULL_BEGIN
     }
     DataSourcePath *instance = [DataSourcePath new];
     instance.filePath = fileUrl.path;
+    instance.shouldDeleteOnDeallocation = shouldDeleteOnDeallocation;
     return instance;
 }
 
 + (nullable DataSource *)dataSourceWithFilePath:(NSString *)filePath
+                     shouldDeleteOnDeallocation:(BOOL)shouldDeleteOnDeallocation
 {
     OWSAssert(filePath);
 
@@ -291,7 +289,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     DataSourcePath *instance = [DataSourcePath new];
     instance.filePath = filePath;
-    OWSAssert(!instance.shouldDeleteOnDeallocation);
+    instance.shouldDeleteOnDeallocation = shouldDeleteOnDeallocation;
     return instance;
 }
 
diff --git a/SignalShareExtension/ShareViewController.swift b/SignalShareExtension/ShareViewController.swift
index 12a65e588..932aa22e3 100644
--- a/SignalShareExtension/ShareViewController.swift
+++ b/SignalShareExtension/ShareViewController.swift
@@ -640,9 +640,11 @@ public class ShareViewController: UIViewController, ShareViewDelegate, SAEFailed
             //
             // NOTE: SharingThreadPickerViewController will try to unpack them
             //       and send them as normal text messages if possible.
-            return DataSourcePath.dataSource(with: url)
+            return DataSourcePath.dataSource(with: url,
+                                             shouldDeleteOnDeallocation: false)
         } else {
-            guard let dataSource = DataSourcePath.dataSource(with: url) else {
+            guard let dataSource = DataSourcePath.dataSource(with: url,
+                                                             shouldDeleteOnDeallocation: false) else {
                 return nil
             }