diff --git a/ServiceLayer/Sources/ServiceLayer/Services/AccountListService.swift b/ServiceLayer/Sources/ServiceLayer/Services/AccountListService.swift
index f963c80..d91c97b 100644
--- a/ServiceLayer/Sources/ServiceLayer/Services/AccountListService.swift
+++ b/ServiceLayer/Sources/ServiceLayer/Services/AccountListService.swift
@@ -8,14 +8,14 @@ import MastodonAPI
 
 public struct AccountListService {
     public let sections: AnyPublisher<[[CollectionItem]], Error>
-    public let nextPageMaxIDs: AnyPublisher<String?, Never>
+    public let nextPageMaxIDs: AnyPublisher<String, Never>
     public let navigationService: NavigationService
 
     private let list: AccountList
     private let endpoint: AccountsEndpoint
     private let mastodonAPIClient: MastodonAPIClient
     private let contentDatabase: ContentDatabase
-    private let nextPageMaxIDsSubject = PassthroughSubject<String?, Never>()
+    private let nextPageMaxIDsSubject = PassthroughSubject<String, Never>()
 
     init(endpoint: AccountsEndpoint, mastodonAPIClient: MastodonAPIClient, contentDatabase: ContentDatabase) {
         list = AccountList()
@@ -33,7 +33,11 @@ public struct AccountListService {
 extension AccountListService: CollectionService {
     public func request(maxID: String?, minID: String?) -> AnyPublisher<Never, Error> {
         mastodonAPIClient.pagedRequest(endpoint, maxID: maxID, minID: minID)
-            .handleEvents(receiveOutput: { nextPageMaxIDsSubject.send($0.info.maxID) })
+            .handleEvents(receiveOutput: {
+                guard let maxID = $0.info.maxID else { return }
+
+                nextPageMaxIDsSubject.send(maxID)
+            })
             .flatMap { contentDatabase.append(accounts: $0.result, toList: list) }
             .eraseToAnyPublisher()
     }
diff --git a/ServiceLayer/Sources/ServiceLayer/Services/CollectionService.swift b/ServiceLayer/Sources/ServiceLayer/Services/CollectionService.swift
index b584588..59459e8 100644
--- a/ServiceLayer/Sources/ServiceLayer/Services/CollectionService.swift
+++ b/ServiceLayer/Sources/ServiceLayer/Services/CollectionService.swift
@@ -4,14 +4,17 @@ import Combine
 
 public protocol CollectionService {
     var sections: AnyPublisher<[[CollectionItem]], Error> { get }
-    var nextPageMaxIDs: AnyPublisher<String?, Never> { get }
+    var nextPageMaxIDs: AnyPublisher<String, Never> { get }
+    var title: AnyPublisher<String, Never> { get }
     var navigationService: NavigationService { get }
-    var title: String? { get }
     var contextParentID: String? { get }
     func request(maxID: String?, minID: String?) -> AnyPublisher<Never, Error>
 }
 
 extension CollectionService {
-    public var title: String? { nil }
+    public var nextPageMaxIDs: AnyPublisher<String, Never> { Empty().eraseToAnyPublisher() }
+
+    public var title: AnyPublisher<String, Never> { Empty().eraseToAnyPublisher() }
+
     public var contextParentID: String? { nil }
 }
diff --git a/ServiceLayer/Sources/ServiceLayer/Services/ContextService.swift b/ServiceLayer/Sources/ServiceLayer/Services/ContextService.swift
index 7914bfd..55e33d2 100644
--- a/ServiceLayer/Sources/ServiceLayer/Services/ContextService.swift
+++ b/ServiceLayer/Sources/ServiceLayer/Services/ContextService.swift
@@ -9,8 +9,6 @@ import MastodonAPI
 public struct ContextService {
     public let sections: AnyPublisher<[[CollectionItem]], Error>
     public let navigationService: NavigationService
-    public let nextPageMaxIDs: AnyPublisher<String?, Never> = Empty().eraseToAnyPublisher()
-    public let title: String? = nil
     public var contextParentID: String? { statusID }
 
     private let statusID: String
diff --git a/ServiceLayer/Sources/ServiceLayer/Services/TimelineService.swift b/ServiceLayer/Sources/ServiceLayer/Services/TimelineService.swift
index ac33a8c..ae4b8a6 100644
--- a/ServiceLayer/Sources/ServiceLayer/Services/TimelineService.swift
+++ b/ServiceLayer/Sources/ServiceLayer/Services/TimelineService.swift
@@ -9,14 +9,14 @@ import MastodonAPI
 public struct TimelineService {
     public let sections: AnyPublisher<[[CollectionItem]], Error>
     public let navigationService: NavigationService
-    public let nextPageMaxIDs: AnyPublisher<String?, Never>
-    public let title: String?
+    public let nextPageMaxIDs: AnyPublisher<String, Never>
+    public let title: AnyPublisher<String, Never>
     public let contextParentID: String? = nil
 
     private let timeline: Timeline
     private let mastodonAPIClient: MastodonAPIClient
     private let contentDatabase: ContentDatabase
-    private let nextPageMaxIDsSubject = PassthroughSubject<String?, Never>()
+    private let nextPageMaxIDsSubject = PassthroughSubject<String, Never>()
 
     init(timeline: Timeline, mastodonAPIClient: MastodonAPIClient, contentDatabase: ContentDatabase) {
         self.timeline = timeline
@@ -27,9 +27,9 @@ public struct TimelineService {
         nextPageMaxIDs = nextPageMaxIDsSubject.eraseToAnyPublisher()
 
         if case let .tag(tag) = timeline {
-            title = "#".appending(tag)
+            title = Just("#".appending(tag)).eraseToAnyPublisher()
         } else {
-            title = nil
+            title = Empty().eraseToAnyPublisher()
         }
     }
 }
@@ -37,7 +37,11 @@ public struct TimelineService {
 extension TimelineService: CollectionService {
     public func request(maxID: String?, minID: String?) -> AnyPublisher<Never, Error> {
         mastodonAPIClient.pagedRequest(timeline.endpoint, maxID: maxID, minID: minID)
-            .handleEvents(receiveOutput: { nextPageMaxIDsSubject.send($0.info.maxID) })
+            .handleEvents(receiveOutput: {
+                guard let maxID = $0.info.maxID else { return }
+
+                nextPageMaxIDsSubject.send(maxID)
+            })
             .flatMap { contentDatabase.insert(statuses: $0.result, timeline: timeline) }
             .eraseToAnyPublisher()
     }
diff --git a/ViewModels/Sources/ViewModels/CollectionItemsViewModel.swift b/ViewModels/Sources/ViewModels/CollectionItemsViewModel.swift
index 849418a..1ef1129 100644
--- a/ViewModels/Sources/ViewModels/CollectionItemsViewModel.swift
+++ b/ViewModels/Sources/ViewModels/CollectionItemsViewModel.swift
@@ -38,7 +38,7 @@ extension CollectionItemsViewModel: CollectionViewModel {
         items.map { $0.map { $0.map(CollectionItemIdentifier.init(item:)) } }.eraseToAnyPublisher()
     }
 
-    public var title: AnyPublisher<String?, Never> { Just(collectionService.title).eraseToAnyPublisher() }
+    public var title: AnyPublisher<String, Never> { collectionService.title }
 
     public var alertItems: AnyPublisher<AlertItem, Never> { $alertItem.compactMap { $0 }.eraseToAnyPublisher() }
 
diff --git a/ViewModels/Sources/ViewModels/CollectionViewModel.swift b/ViewModels/Sources/ViewModels/CollectionViewModel.swift
index 2ad616c..b68a091 100644
--- a/ViewModels/Sources/ViewModels/CollectionViewModel.swift
+++ b/ViewModels/Sources/ViewModels/CollectionViewModel.swift
@@ -5,7 +5,7 @@ import Foundation
 
 public protocol CollectionViewModel {
     var sections: AnyPublisher<[[CollectionItemIdentifier]], Never> { get }
-    var title: AnyPublisher<String?, Never> { get }
+    var title: AnyPublisher<String, Never> { get }
     var alertItems: AnyPublisher<AlertItem, Never> { get }
     var loading: AnyPublisher<Bool, Never> { get }
     var navigationEvents: AnyPublisher<NavigationEvent, Never> { get }
diff --git a/ViewModels/Sources/ViewModels/ProfileViewModel.swift b/ViewModels/Sources/ViewModels/ProfileViewModel.swift
index 9e3434a..bb7048b 100644
--- a/ViewModels/Sources/ViewModels/ProfileViewModel.swift
+++ b/ViewModels/Sources/ViewModels/ProfileViewModel.swift
@@ -43,8 +43,8 @@ extension ProfileViewModel: CollectionViewModel {
         collectionViewModel.flatMap(\.sections).eraseToAnyPublisher()
     }
 
-    public var title: AnyPublisher<String?, Never> {
-        $accountViewModel.map { $0?.accountName }.eraseToAnyPublisher()
+    public var title: AnyPublisher<String, Never> {
+        $accountViewModel.compactMap { $0?.accountName }.eraseToAnyPublisher()
     }
 
     public var alertItems: AnyPublisher<AlertItem, Never> {