diff --git a/Mac/MainWindow/MainWindowController.swift b/Mac/MainWindow/MainWindowController.swift
index d9523f961..c5159dc8b 100644
--- a/Mac/MainWindow/MainWindowController.swift
+++ b/Mac/MainWindow/MainWindowController.swift
@@ -426,15 +426,12 @@ class MainWindowController : NSWindowController, NSUserInterfaceValidations {
 extension MainWindowController: NSWindowDelegate {
 	
 	func window(_ window: NSWindow, willEncodeRestorableState coder: NSCoder) {
-		saveSplitViewState(to: coder)
-		sidebarViewController?.saveState(to: coder)
-		timelineContainerViewController?.saveState(to: coder)
+		coder.encode(savableState(), forKey: UserInfoKey.windowState)
 	}
 
 	func window(_ window: NSWindow, didDecodeRestorableState coder: NSCoder) {
-		restoreSplitViewState(from: coder)
-		sidebarViewController?.restoreState(from: coder)
-		timelineContainerViewController?.restoreState(from: coder)
+		guard let state = try? coder.decodeTopLevelObject(forKey: UserInfoKey.windowState) as? [AnyHashable : Any] else { return }
+		restoreState(from: state)
 	}
 
 	func windowWillClose(_ notification: Notification) {
@@ -704,6 +701,22 @@ private extension MainWindowController {
 		return oneSelectedArticle?.preferredLink
 	}
 
+	// MARK: - State Restoration
+	
+	func savableState() -> [AnyHashable : Any] {
+		var state = [AnyHashable : Any]()
+		saveSplitViewState(to: &state)
+		sidebarViewController?.saveState(to: &state)
+		timelineContainerViewController?.saveState(to: &state)
+		return state
+	}
+
+	func restoreState(from state: [AnyHashable : Any]) {
+		restoreSplitViewState(from: state)
+		sidebarViewController?.restoreState(from: state)
+		timelineContainerViewController?.restoreState(from: state)
+	}
+
 	// MARK: - Command Validation
 
 	func canGoToNextUnread() -> Bool {
@@ -912,18 +925,18 @@ private extension MainWindowController {
 		}
 	}
 
-	func saveSplitViewState(to coder: NSCoder) {
+	func saveSplitViewState(to state: inout [AnyHashable : Any]) {
 		guard let splitView = splitViewController?.splitView else {
 			return
 		}
 
 		let widths = splitView.arrangedSubviews.map{ Int(floor($0.frame.width)) }
-		coder.encode(widths, forKey: MainWindowController.mainWindowWidthsStateKey)
+		state[MainWindowController.mainWindowWidthsStateKey] = widths
 	}
 
-	func restoreSplitViewState(from coder: NSCoder) {
+	func restoreSplitViewState(from state: [AnyHashable : Any]) {
 		guard let splitView = splitViewController?.splitView,
-			let widths = try? coder.decodeTopLevelObject(forKey: MainWindowController.mainWindowWidthsStateKey) as? [Int],
+			let widths = state[MainWindowController.mainWindowWidthsStateKey] as? [Int],
 			widths.count == 3,
 			let window = window else {
 				return
diff --git a/Mac/MainWindow/Sidebar/SidebarViewController.swift b/Mac/MainWindow/Sidebar/SidebarViewController.swift
index 5f42cd10c..cb5b688e5 100644
--- a/Mac/MainWindow/Sidebar/SidebarViewController.swift
+++ b/Mac/MainWindow/Sidebar/SidebarViewController.swift
@@ -90,20 +90,20 @@ protocol SidebarDelegate: class {
 
 	// MARK: State Restoration
 	
-	func saveState(to coder: NSCoder) {
-		coder.encode(isReadFiltered, forKey: UserInfoKey.readFeedsFilterState)
-		coder.encode(expandedTable.map( { $0.userInfo }), forKey: UserInfoKey.containerExpandedWindowState)
-		coder.encode(selectedFeeds.compactMap({ $0.feedID?.userInfo }), forKey: UserInfoKey.selectedFeedsState)
+	func saveState(to state: inout [AnyHashable : Any]) {
+		state[UserInfoKey.readFeedsFilterState] = isReadFiltered
+		state[UserInfoKey.containerExpandedWindowState] = expandedTable.map { $0.userInfo }
+		state[UserInfoKey.selectedFeedsState] = selectedFeeds.compactMap { $0.feedID?.userInfo }
 	}
 	
-	func restoreState(from coder: NSCoder) {
+	func restoreState(from state: [AnyHashable : Any]) {
 		
-		if let containerExpandedWindowState = try? coder.decodeTopLevelObject(forKey: UserInfoKey.containerExpandedWindowState) as? [[AnyHashable: AnyHashable]] {
+		if let containerExpandedWindowState = state[UserInfoKey.containerExpandedWindowState] as? [[AnyHashable: AnyHashable]] {
 			let containerIdentifers = containerExpandedWindowState.compactMap( { ContainerIdentifier(userInfo: $0) })
 			expandedTable = Set(containerIdentifers)
 		}
 
-		guard let selectedFeedsState = try? coder.decodeTopLevelObject(forKey: UserInfoKey.selectedFeedsState) as? [[AnyHashable: AnyHashable]] else {
+		guard let selectedFeedsState = state[UserInfoKey.selectedFeedsState] as? [[AnyHashable: AnyHashable]] else {
 			return
 		}
 
@@ -126,7 +126,9 @@ protocol SidebarDelegate: class {
 		outlineView.selectRowIndexes(selectIndexes, byExtendingSelection: false)
 		focus()
 		
-		isReadFiltered = coder.decodeBool(forKey: UserInfoKey.readFeedsFilterState)
+		if let readFeedsFilterState = state[UserInfoKey.readFeedsFilterState] as? Bool {
+			isReadFiltered = readFeedsFilterState
+		}
 	}
 	
 	// MARK: - Notifications
diff --git a/Mac/MainWindow/Timeline/TimelineContainerViewController.swift b/Mac/MainWindow/Timeline/TimelineContainerViewController.swift
index 9dcefff47..159278ade 100644
--- a/Mac/MainWindow/Timeline/TimelineContainerViewController.swift
+++ b/Mac/MainWindow/Timeline/TimelineContainerViewController.swift
@@ -95,12 +95,12 @@ final class TimelineContainerViewController: NSViewController {
 	
 	// MARK: State Restoration
 	
-	func saveState(to coder: NSCoder) {
-		regularTimelineViewController.saveState(to: coder)
+	func saveState(to state: inout [AnyHashable : Any]) {
+		regularTimelineViewController.saveState(to: &state)
 	}
 	
-	func restoreState(from coder: NSCoder) {
-		regularTimelineViewController.restoreState(from: coder)
+	func restoreState(from state: [AnyHashable : Any]) {
+		regularTimelineViewController.restoreState(from: state)
 	}
 }
 
diff --git a/Mac/MainWindow/Timeline/TimelineViewController.swift b/Mac/MainWindow/Timeline/TimelineViewController.swift
index 6e1de56b5..d88c5721b 100644
--- a/Mac/MainWindow/Timeline/TimelineViewController.swift
+++ b/Mac/MainWindow/Timeline/TimelineViewController.swift
@@ -247,20 +247,20 @@ final class TimelineViewController: NSViewController, UndoableCommandRunner, Unr
 	
 	// MARK: State Restoration
 	
-	func saveState(to coder: NSCoder) {
+	func saveState(to state: inout [AnyHashable : Any]) {
 		var readArticlesFilterState = [[AnyHashable: AnyHashable]: Bool]()
 		for key in readFilterEnabledTable.keys {
 			readArticlesFilterState[key.userInfo] = readFilterEnabledTable[key]
 		}
-		coder.encode(readArticlesFilterState, forKey: UserInfoKey.readArticlesFilterState)
+		state[UserInfoKey.readArticlesFilterState] = readArticlesFilterState
 		
 		if selectedArticles.count == 1 {
-			coder.encode(selectedArticles.first!.pathUserInfo, forKey: UserInfoKey.articlePath)
+			state[UserInfoKey.articlePath] = selectedArticles.first!.pathUserInfo
 		}
 	}
 	
-	func restoreState(from coder: NSCoder) {
-		if let readArticlesFilterState = try? coder.decodeTopLevelObject(forKey: UserInfoKey.readArticlesFilterState) as? [[AnyHashable: AnyHashable]: Bool] {
+	func restoreState(from state: [AnyHashable : Any]) {
+		if let readArticlesFilterState = state[UserInfoKey.readArticlesFilterState] as? [[AnyHashable: AnyHashable]: Bool] {
 			for key in readArticlesFilterState.keys {
 				if let feedIdentifier = FeedIdentifier(userInfo: key) {
 					readFilterEnabledTable[feedIdentifier] = readArticlesFilterState[key]
@@ -268,7 +268,7 @@ final class TimelineViewController: NSViewController, UndoableCommandRunner, Unr
 			}
 		}
 		
-		guard let articlePathUserInfo = try? coder.decodeTopLevelObject(forKey: UserInfoKey.articlePath) as? [AnyHashable : Any],
+		guard let articlePathUserInfo = state[UserInfoKey.articlePath] as? [AnyHashable : Any],
 			let accountID = articlePathUserInfo[ArticlePathKey.accountID] as? String,
 			let account = AccountManager.shared.existingAccount(with: accountID),
 			let articleID = articlePathUserInfo[ArticlePathKey.articleID] as? String else {