diff --git a/Podfile.lock b/Podfile.lock
index 6fa28f32d..9d586765a 100644
--- a/Podfile.lock
+++ b/Podfile.lock
@@ -132,7 +132,7 @@ CHECKOUT OPTIONS:
     :commit: cbf2f47d59dd54d6d720fe787f835bd767443bb6
     :git: https://github.com/WhisperSystems/SignalProtocolKit.git
   SignalServiceKit:
-    :commit: 8b5f82eb6d8393074987697cea6986b55fec800e
+    :commit: e4ec7298441e82c8c5cd0678ea165dc3e12b2986
     :git: https://github.com/WhisperSystems/SignalServiceKit.git
   SocketRocket:
     :commit: 877ac7438be3ad0b45ef5ca3969574e4b97112bf
diff --git a/Signal/src/UserInterface/Notifications/CallNotificationsAdapter.swift b/Signal/src/UserInterface/Notifications/CallNotificationsAdapter.swift
index 3cfd2ca12..d2363ab3c 100644
--- a/Signal/src/UserInterface/Notifications/CallNotificationsAdapter.swift
+++ b/Signal/src/UserInterface/Notifications/CallNotificationsAdapter.swift
@@ -21,7 +21,7 @@ class CallNotificationsAdapter: NSObject {
 //        if #available(iOS 10.0, *) {
 //            adaptee = UserNotificationsAdaptee()
 //        } else {
-            adaptee = NotificationsManager()
+            adaptee = Environment.getCurrent().notificationsManager
 //        }
     }
 
diff --git a/Signal/src/contact/OWSContactsManager.m b/Signal/src/contact/OWSContactsManager.m
index 8001c7f84..ce7c32f86 100644
--- a/Signal/src/contact/OWSContactsManager.m
+++ b/Signal/src/contact/OWSContactsManager.m
@@ -41,6 +41,8 @@ NSString *const OWSContactsManagerSignalRecipientsDidChangeNotification =
     _latestContactsById = @{};
     _avatarCache = [NSCache new];
 
+    OWSSingletonAssert();
+
     return self;
 }
 
diff --git a/Signal/src/environment/Environment.m b/Signal/src/environment/Environment.m
index 76da3d1b1..a2f3d474c 100644
--- a/Signal/src/environment/Environment.m
+++ b/Signal/src/environment/Environment.m
@@ -52,6 +52,8 @@ static Environment *environment = nil;
     _networkManager = networkManager;
     _messageSender = messageSender;
 
+    OWSSingletonAssert();
+
     return self;
 }
 
diff --git a/Signal/src/environment/NotificationsManager.m b/Signal/src/environment/NotificationsManager.m
index 038d6a051..1a2d8261c 100644
--- a/Signal/src/environment/NotificationsManager.m
+++ b/Signal/src/environment/NotificationsManager.m
@@ -17,12 +17,14 @@
 
 @interface NotificationsManager ()
 
-@property SystemSoundID newMessageSound;
+@property (nonatomic) SystemSoundID newMessageSound;
 @property (nonatomic, readonly) NSMutableDictionary<NSString *, UILocalNotification *> *currentNotifications;
 @property (nonatomic, readonly) NotificationType notificationPreviewType;
 
 @end
 
+#pragma mark -
+
 @implementation NotificationsManager
 
 - (instancetype)init
@@ -37,6 +39,8 @@
     NSURL *newMessageURL = [[NSBundle mainBundle] URLForResource:@"NewMessage" withExtension:@"aifc"];
     AudioServicesCreateSystemSoundID((__bridge CFURLRef)newMessageURL, &_newMessageSound);
 
+    OWSSingletonAssert();
+
     return self;
 }
 
diff --git a/Signal/src/environment/PropertyListPreferences.m b/Signal/src/environment/PropertyListPreferences.m
index e2f628bc7..7f65b46ec 100644
--- a/Signal/src/environment/PropertyListPreferences.m
+++ b/Signal/src/environment/PropertyListPreferences.m
@@ -29,6 +29,18 @@ NSString *const PropertyListPreferencesKeyHasDeclinedNoContactsView = @"hasDecli
 
 @implementation PropertyListPreferences
 
+- (instancetype)init
+{
+    self = [super init];
+    if (!self) {
+        return self;
+    }
+
+    OWSSingletonAssert();
+
+    return self;
+}
+
 #pragma mark - Helpers
 
 - (void)clear {
diff --git a/Signal/src/network/PushManager.h b/Signal/src/network/PushManager.h
index a2849c877..97039713a 100644
--- a/Signal/src/network/PushManager.h
+++ b/Signal/src/network/PushManager.h
@@ -39,6 +39,8 @@ typedef void (^pushTokensSuccessBlock)(NSString *pushToken, NSString *voipToken)
 
 @interface PushManager : NSObject <PKPushRegistryDelegate>
 
+- (instancetype)init NS_UNAVAILABLE;
+
 + (PushManager *)sharedManager;
 
 /**
diff --git a/Signal/src/network/PushManager.m b/Signal/src/network/PushManager.m
index 5fff2fdfb..420fab28e 100644
--- a/Signal/src/network/PushManager.m
+++ b/Signal/src/network/PushManager.m
@@ -77,6 +77,8 @@
     _callBackgroundTask = UIBackgroundTaskInvalid;
     _currentNotifications = [NSMutableArray array];
 
+    OWSSingletonAssert();
+
     return self;
 }
 
diff --git a/Signal/src/util/Pastelog.m b/Signal/src/util/Pastelog.m
index f8a990256..c5bbb53cf 100644
--- a/Signal/src/util/Pastelog.m
+++ b/Signal/src/util/Pastelog.m
@@ -103,6 +103,8 @@
 -(instancetype)init {
     if (self = [super init]) {
         self.responseData = [NSMutableData data];
+
+        OWSSingletonAssert();
     }
     return self;
 }