diff --git a/Podfile.lock b/Podfile.lock
index 39689314a..df4b8d03c 100644
--- a/Podfile.lock
+++ b/Podfile.lock
@@ -134,7 +134,7 @@ CHECKOUT OPTIONS:
     :commit: 521686c112bbae7a762f85d52b1e41eeb1760772
     :git: https://github.com/WhisperSystems/JSQMessagesViewController.git
   SignalServiceKit:
-    :commit: ed249840c61ab48a7fcd762d7d4b01dc78dff0a6
+    :commit: 2315ab79de5fad39c3a285ff74d2fc8d62211eab
     :git: https://github.com/WhisperSystems/SignalServiceKit.git
   SocketRocket:
     :commit: 877ac7438be3ad0b45ef5ca3969574e4b97112bf
diff --git a/Signal.xcodeproj/project.pbxproj b/Signal.xcodeproj/project.pbxproj
index 0706ac717..26f18ea80 100644
--- a/Signal.xcodeproj/project.pbxproj
+++ b/Signal.xcodeproj/project.pbxproj
@@ -14,6 +14,7 @@
 		340CB2271EAC25820001CAA1 /* UpdateGroupViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = 340CB2261EAC25820001CAA1 /* UpdateGroupViewController.m */; };
 		341207271EE19F6A00463194 /* OWSSystemMessageCell.m in Sources */ = {isa = PBXBuildFile; fileRef = 341207261EE19F6A00463194 /* OWSSystemMessageCell.m */; };
 		341BB7491DB727EE001E2975 /* JSQMediaItem+OWS.m in Sources */ = {isa = PBXBuildFile; fileRef = 341BB7481DB727EE001E2975 /* JSQMediaItem+OWS.m */; };
+		342FCE6B1EF9C375002690AD /* OWS105AttachmentFilePaths.m in Sources */ = {isa = PBXBuildFile; fileRef = 342FCE6A1EF9C375002690AD /* OWS105AttachmentFilePaths.m */; };
 		34330A5A1E7875FB00DF2FB9 /* fontawesome-webfont.ttf in Resources */ = {isa = PBXBuildFile; fileRef = 34330A591E7875FB00DF2FB9 /* fontawesome-webfont.ttf */; };
 		34330A5C1E787A9800DF2FB9 /* dripicons-v2.ttf in Resources */ = {isa = PBXBuildFile; fileRef = 34330A5B1E787A9800DF2FB9 /* dripicons-v2.ttf */; };
 		34330A5E1E787BD800DF2FB9 /* ElegantIcons.ttf in Resources */ = {isa = PBXBuildFile; fileRef = 34330A5D1E787BD800DF2FB9 /* ElegantIcons.ttf */; };
@@ -376,6 +377,8 @@
 		341207261EE19F6A00463194 /* OWSSystemMessageCell.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; lineEnding = 0; path = OWSSystemMessageCell.m; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.objc; };
 		341BB7471DB727EE001E2975 /* JSQMediaItem+OWS.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "JSQMediaItem+OWS.h"; sourceTree = "<group>"; };
 		341BB7481DB727EE001E2975 /* JSQMediaItem+OWS.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "JSQMediaItem+OWS.m"; sourceTree = "<group>"; };
+		342FCE691EF9C375002690AD /* OWS105AttachmentFilePaths.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = OWS105AttachmentFilePaths.h; path = Migrations/OWS105AttachmentFilePaths.h; sourceTree = "<group>"; };
+		342FCE6A1EF9C375002690AD /* OWS105AttachmentFilePaths.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = OWS105AttachmentFilePaths.m; path = Migrations/OWS105AttachmentFilePaths.m; sourceTree = "<group>"; };
 		34330A591E7875FB00DF2FB9 /* fontawesome-webfont.ttf */ = {isa = PBXFileReference; lastKnownFileType = file; path = "fontawesome-webfont.ttf"; sourceTree = "<group>"; };
 		34330A5B1E787A9800DF2FB9 /* dripicons-v2.ttf */ = {isa = PBXFileReference; lastKnownFileType = file; path = "dripicons-v2.ttf"; sourceTree = "<group>"; };
 		34330A5D1E787BD800DF2FB9 /* ElegantIcons.ttf */ = {isa = PBXFileReference; lastKnownFileType = file; path = ElegantIcons.ttf; sourceTree = "<group>"; };
@@ -1093,10 +1096,6 @@
 		45666F731D9BFDB9008FE134 /* Migrations */ = {
 			isa = PBXGroup;
 			children = (
-				45666F791D9C0533008FE134 /* OWSDatabaseMigration.h */,
-				45666F7A1D9C0533008FE134 /* OWSDatabaseMigration.m */,
-				45666F7C1D9C0814008FE134 /* OWSDatabaseMigrationRunner.h */,
-				45666F7D1D9C0814008FE134 /* OWSDatabaseMigrationRunner.m */,
 				45666F741D9BFE00008FE134 /* OWS100RemoveTSRecipientsMigration.h */,
 				45666F751D9BFE00008FE134 /* OWS100RemoveTSRecipientsMigration.m */,
 				4516E3FD1DD2193B00DC4206 /* OWS101ExistingUsersBlockOnIdentityChange.h */,
@@ -1107,6 +1106,12 @@
 				450573FD1E78A06D00615BB4 /* OWS103EnableVideoCalling.m */,
 				4585C45E1ED4FD0400896AEA /* OWS104CreateRecipientIdentities.h */,
 				4585C45F1ED4FD0400896AEA /* OWS104CreateRecipientIdentities.m */,
+				342FCE691EF9C375002690AD /* OWS105AttachmentFilePaths.h */,
+				342FCE6A1EF9C375002690AD /* OWS105AttachmentFilePaths.m */,
+				45666F791D9C0533008FE134 /* OWSDatabaseMigration.h */,
+				45666F7A1D9C0533008FE134 /* OWSDatabaseMigration.m */,
+				45666F7C1D9C0814008FE134 /* OWSDatabaseMigrationRunner.h */,
+				45666F7D1D9C0814008FE134 /* OWSDatabaseMigrationRunner.m */,
 			);
 			name = Migrations;
 			sourceTree = "<group>";
@@ -2117,6 +2122,7 @@
 				76EB057A18170B33006006FC /* OWSContactsManager.m in Sources */,
 				76EB064218170B33006006FC /* StringUtil.m in Sources */,
 				452037D11EE84975004E4CDF /* DebugUISessionState.m in Sources */,
+				342FCE6B1EF9C375002690AD /* OWS105AttachmentFilePaths.m in Sources */,
 				45BFFFA81D898AF0004A12A7 /* OWSStaleNotificationObserver.m in Sources */,
 				45C681B71D305A580050903A /* OWSCall.m in Sources */,
 				76EB062618170B33006006FC /* Queue.m in Sources */,
diff --git a/Signal/src/environment/Migrations/OWS102MoveLoggingPreferenceToUserDefaults.m b/Signal/src/environment/Migrations/OWS102MoveLoggingPreferenceToUserDefaults.m
index f7935506c..d80c2e70a 100644
--- a/Signal/src/environment/Migrations/OWS102MoveLoggingPreferenceToUserDefaults.m
+++ b/Signal/src/environment/Migrations/OWS102MoveLoggingPreferenceToUserDefaults.m
@@ -41,7 +41,6 @@ static NSString *const OWS102MoveLoggingPreferenceToUserDefaultsMigrationId = @"
     }
 }
 
-
 #pragma mark - Logging
 
 + (NSString *)tag
diff --git a/Signal/src/environment/Migrations/OWS105AttachmentFilePaths.h b/Signal/src/environment/Migrations/OWS105AttachmentFilePaths.h
new file mode 100644
index 000000000..a9fbfb6d1
--- /dev/null
+++ b/Signal/src/environment/Migrations/OWS105AttachmentFilePaths.h
@@ -0,0 +1,13 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+#import "OWSDatabaseMigration.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface OWS105AttachmentFilePaths : OWSDatabaseMigration
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Signal/src/environment/Migrations/OWS105AttachmentFilePaths.m b/Signal/src/environment/Migrations/OWS105AttachmentFilePaths.m
new file mode 100644
index 000000000..f096e3ae8
--- /dev/null
+++ b/Signal/src/environment/Migrations/OWS105AttachmentFilePaths.m
@@ -0,0 +1,59 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+#import "OWS105AttachmentFilePaths.h"
+#import <SignalServiceKit/TSAttachmentStream.h>
+#import <YapDatabase/YapDatabaseTransaction.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+// Increment a similar constant for every future DBMigration
+static NSString *const OWS105AttachmentFilePathsMigrationId = @"105";
+
+@implementation OWS105AttachmentFilePaths
+
++ (NSString *)migrationId
+{
+    return OWS105AttachmentFilePathsMigrationId;
+}
+
+- (void)runUpWithTransaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    OWSAssert(transaction);
+
+    NSMutableArray<TSAttachmentStream *> *attachmentStreams = [NSMutableArray new];
+    [transaction enumerateKeysAndObjectsInCollection:TSAttachmentStream.collection
+                                          usingBlock:^(NSString *key, TSAttachment *attachment, BOOL *stop) {
+                                              if (![attachment isKindOfClass:[TSAttachmentStream class]]) {
+                                                  return;
+                                              }
+                                              TSAttachmentStream *attachmentStream = (TSAttachmentStream *)attachment;
+                                              [attachmentStreams addObject:attachmentStream];
+                                          }];
+
+    DDLogInfo(@"Saving %zd attachment streams.", attachmentStreams.count);
+
+    // Persist the new localRelativeFilePath property of TSAttachmentStream.
+    // For performance, we want to upgrade all existing attachment streams in
+    // a single transaction.
+    for (TSAttachmentStream *attachmentStream in attachmentStreams) {
+        [attachmentStream saveWithTransaction:transaction];
+    }
+}
+
+#pragma mark - Logging
+
++ (NSString *)tag
+{
+    return [NSString stringWithFormat:@"[%@]", self.class];
+}
+
+- (NSString *)tag
+{
+    return self.class.tag;
+}
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Signal/src/environment/Migrations/OWSDatabaseMigrationRunner.m b/Signal/src/environment/Migrations/OWSDatabaseMigrationRunner.m
index d3a0434f4..d2a6c6d07 100644
--- a/Signal/src/environment/Migrations/OWSDatabaseMigrationRunner.m
+++ b/Signal/src/environment/Migrations/OWSDatabaseMigrationRunner.m
@@ -7,6 +7,7 @@
 #import "OWS102MoveLoggingPreferenceToUserDefaults.h"
 #import "OWS103EnableVideoCalling.h"
 #import "OWS104CreateRecipientIdentities.h"
+#import "OWS105AttachmentFilePaths.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -30,7 +31,8 @@ NS_ASSUME_NONNULL_BEGIN
         [[OWS100RemoveTSRecipientsMigration alloc] initWithStorageManager:self.storageManager],
         [[OWS102MoveLoggingPreferenceToUserDefaults alloc] initWithStorageManager:self.storageManager],
         [[OWS103EnableVideoCalling alloc] initWithStorageManager:self.storageManager],
-        [[OWS104CreateRecipientIdentities alloc] initWithStorageManager:self.storageManager]
+        [[OWS104CreateRecipientIdentities alloc] initWithStorageManager:self.storageManager],
+        [[OWS105AttachmentFilePaths alloc] initWithStorageManager:self.storageManager]
     ];
 }