diff --git a/English.lproj/MainMenu.xib b/English.lproj/MainMenu.xib
index 5378e5b..8def9ed 100644
--- a/English.lproj/MainMenu.xib
+++ b/English.lproj/MainMenu.xib
@@ -771,9 +771,6 @@
 			<object class="NSCustomObject" id="269446200">
 				<string key="NSClassName">RemoteHostsManager</string>
 			</object>
-			<object class="NSCustomObject" id="354390743">
-				<string key="NSClassName">SUUpdater</string>
-			</object>
 		</array>
 		<object class="IBObjectContainer" key="IBDocument.Objects">
 			<array key="connectionRecords">
@@ -1190,12 +1187,12 @@
 					<int key="connectionID">552</int>
 				</object>
 				<object class="IBConnectionRecord">
-					<object class="IBActionConnection" key="connection">
-						<string key="label">checkForUpdates:</string>
-						<reference key="source" ref="354390743"/>
+					<object class="IBOutletConnection" key="connection">
+						<string key="label">checkForUpdatesMenuItem</string>
+						<reference key="source" ref="82089617"/>
 						<reference key="destination" ref="263053057"/>
 					</object>
-					<int key="connectionID">606</int>
+					<int key="connectionID">623</int>
 				</object>
 				<object class="IBConnectionRecord">
 					<object class="IBBindingConnection" key="connection">
@@ -1795,11 +1792,6 @@
 						<reference key="object" ref="1023338729"/>
 						<reference key="parent" ref="110575045"/>
 					</object>
-					<object class="IBObjectRecord">
-						<int key="objectID">605</int>
-						<reference key="object" ref="354390743"/>
-						<reference key="parent" ref="0"/>
-					</object>
 					<object class="IBObjectRecord">
 						<int key="objectID">609</int>
 						<reference key="object" ref="155258003"/>
@@ -1897,7 +1889,6 @@
 				<string key="602.IBPluginDependency">com.apple.InterfaceBuilder.CocoaPlugin</string>
 				<string key="603.IBPluginDependency">com.apple.InterfaceBuilder.CocoaPlugin</string>
 				<string key="604.IBPluginDependency">com.apple.InterfaceBuilder.CocoaPlugin</string>
-				<string key="605.IBPluginDependency">com.apple.InterfaceBuilder.CocoaPlugin</string>
 				<string key="609.IBPluginDependency">com.apple.InterfaceBuilder.CocoaPlugin</string>
 				<string key="611.IBPluginDependency">com.apple.InterfaceBuilder.CocoaPlugin</string>
 				<string key="614.IBPluginDependency">com.apple.InterfaceBuilder.CocoaPlugin</string>
diff --git a/Gas Mask.xcodeproj/project.pbxproj b/Gas Mask.xcodeproj/project.pbxproj
index a6ea577..30775f1 100644
--- a/Gas Mask.xcodeproj/project.pbxproj	
+++ b/Gas Mask.xcodeproj/project.pbxproj	
@@ -1502,7 +1502,7 @@
 			repositoryURL = "https://github.com/sparkle-project/Sparkle.git";
 			requirement = {
 				kind = exactVersion;
-				version = 1.27.1;
+				version = 2.9.0;
 			};
 		};
 		AA1B2C3D4E5F000300000001 /* XCRemoteSwiftPackageReference "MASShortcut" */ = {
diff --git a/Gas Mask.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved b/Gas Mask.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved
index 891922a..7d4ac8e 100644
--- a/Gas Mask.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved	
+++ b/Gas Mask.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved	
@@ -1,12 +1,11 @@
 {
-  "originHash" : "74784ff33407b9ca71d04ea3acb135980046aa512ad6ef909abb7da8127b1333",
+  "originHash" : "34d6a563af95a9a6489907cf183989fcd49db5e2b85aa1c4f84d6c2e053df114",
   "pins" : [
     {
       "identity" : "masshortcut",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/shpakovski/MASShortcut",
       "state" : {
-        "branch" : "master",
         "revision" : "6f2603c6b6cc18f64a799e5d2c9d3bbc467c413a"
       }
     },
@@ -15,8 +14,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/sparkle-project/Sparkle.git",
       "state" : {
-        "revision" : "7918c1c8fc68baa37917eeaa67286b077ad5e393",
-        "version" : "1.27.1"
+        "revision" : "21d8df80440b1ca3b65fa82e40782f1e5a9e6ba2",
+        "version" : "2.9.0"
       }
     }
   ],
diff --git a/Info.plist b/Info.plist
index bee1ca8..85f039b 100644
--- a/Info.plist
+++ b/Info.plist
@@ -95,6 +95,8 @@
 	<string>http://gmask.clockwise.ee/check_update/</string>
 	<key>SUPublicDSAKeyFile</key>
 	<string>sparkle_dsa_pub.pem</string>
+	<key>SUPublicEDKey</key>
+	<string>REPLACE_WITH_EDDSA_PUBLIC_KEY</string>
 	<key>SUScheduledCheckInterval</key>
 	<string>86400</string>
 	<key>UTExportedTypeDeclarations</key>
diff --git a/Source/ApplicationController.h b/Source/ApplicationController.h
index 8aa3fa8..48d2f41 100644
--- a/Source/ApplicationController.h
+++ b/Source/ApplicationController.h
@@ -21,19 +21,25 @@
 #import "HostsMainController.h"
 
 @class AboutBoxController;
+@class SPUStandardUpdaterController;
+@class SPUUpdater;
 
 @interface ApplicationController : NSObject {
 	@private
 	IBOutlet NSProgressIndicator *busyIndicator;
 	IBOutlet HostsMainController *hostsController;
+	IBOutlet NSMenuItem *checkForUpdatesMenuItem;
 	int busyThreads;
 	BOOL shouldQuit;
 	BOOL editorWindowOpened;
     AboutBoxController *aboutBoxController;
+	SPUStandardUpdaterController *_updaterController;
 }
 
 + (ApplicationController*)defaultInstance;
 
+@property (nonatomic, readonly) SPUUpdater *updater;
+
 - (IBAction)openPreferencesWindow:(id)sender;
 - (IBAction)displayAboutBox:(id)sender;
 - (IBAction)reportBugs:(id)sender;
diff --git a/Source/ApplicationController.m b/Source/ApplicationController.m
index b35f19d..fd830ea 100644
--- a/Source/ApplicationController.m
+++ b/Source/ApplicationController.m
@@ -27,6 +27,7 @@
 #import "LocalHostsController.h"
 #import "RemoteHostsController.h"
 #import "NotificationHelper.h"
+#import <Sparkle/Sparkle.h>
 
 @interface ApplicationController ()
 {
@@ -64,18 +65,31 @@ - (id)init
 	if (self = [super init]) {
 		busyThreads = 0;
 		shouldQuit = YES;
-		
+
+		BOOL isTesting = NSClassFromString(@"XCTestCase") != nil;
+		if (!isTesting) {
+			_updaterController = [[SPUStandardUpdaterController alloc]
+								  initWithStartingUpdater:YES
+								  updaterDelegate:nil
+								  userDriverDelegate:nil];
+		}
+
 		NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
 		[nc addObserver:self selector:@selector(activatePreviousFile:) name:ActivatePreviousFileNotification object:nil];
 		[nc addObserver:self selector:@selector(activateNextFile:) name:ActivateNextFileNotification object:nil];
         [nc addObserver:self selector:@selector(notifyOfFileRestored:) name:RestoredHostsFileNotification object:nil];
-		
+
 		sharedInstance = self;
 		return self;
 	}
     return sharedInstance;
 }
 
+- (SPUUpdater *)updater
+{
+	return _updaterController.updater;
+}
+
 -(IBAction)openPreferencesWindow:(id)sender
 {
     [self showApplicationInDock];
@@ -179,6 +193,9 @@ - (void)applicationWillFinishLaunching:(NSNotification *)aNotification
 {
 	(void)[GlobalShortcuts shared]; // Register global hotkeys
 
+	checkForUpdatesMenuItem.target = _updaterController;
+	checkForUpdatesMenuItem.action = @selector(checkForUpdates:);
+
 	[NSApp setServicesProvider:self];
 
 	[self initStructure];
diff --git a/Source/Swift/GasMask-Bridging-Header.h b/Source/Swift/GasMask-Bridging-Header.h
index 2912fe5..a98982a 100644
--- a/Source/Swift/GasMask-Bridging-Header.h
+++ b/Source/Swift/GasMask-Bridging-Header.h
@@ -14,3 +14,4 @@
 #import "ListController.h"
 #import "Preferences+Remote.h"
 #import "LoginItem.h"
+#import "ApplicationController.h"
diff --git a/Source/Swift/PreferencesView.swift b/Source/Swift/PreferencesView.swift
index c221c6e..77f4586 100644
--- a/Source/Swift/PreferencesView.swift
+++ b/Source/Swift/PreferencesView.swift
@@ -108,7 +108,7 @@ struct UpdateTab: View {
             Button("Check Now") {
                 sparkleObserver.checkForUpdates()
             }
-            .disabled(!sparkleObserver.automaticChecksEnabled)
+            .disabled(!sparkleObserver.canCheckForUpdates)
         }
         .padding(20)
     }
diff --git a/Source/Swift/SparkleObserver.swift b/Source/Swift/SparkleObserver.swift
index 66ee4c1..4dbd203 100644
--- a/Source/Swift/SparkleObserver.swift
+++ b/Source/Swift/SparkleObserver.swift
@@ -1,14 +1,14 @@
+import Combine
 import Foundation
 import Sparkle
 
-/// Wraps `SUUpdater.shared()` as an `ObservableObject` for SwiftUI.
-///
-/// Replaces the XIB-instantiated `SUUpdater` object and `UpdateDateTransformer`.
+/// Wraps `SPUUpdater` as an `ObservableObject` for SwiftUI.
 final class SparkleObserver: ObservableObject {
     @Published var lastCheckDate: Date?
     @Published var automaticChecksEnabled: Bool
+    @Published var canCheckForUpdates = false
 
-    private var dateObservation: NSKeyValueObservation?
+    private let updater: SPUUpdater?
 
     private static let dateFormatter: DateFormatter = {
         let formatter = DateFormatter()
@@ -25,30 +25,40 @@ final class SparkleObserver: ObservableObject {
         return "Last Checked: \(Self.dateFormatter.string(from: date))"
     }
 
-    init() {
-        guard let updater = SUUpdater.shared() else {
-            self.lastCheckDate = nil
-            self.automaticChecksEnabled = false
-            return
-        }
-        self.lastCheckDate = updater.lastUpdateCheckDate
-        self.automaticChecksEnabled = updater.automaticallyChecksForUpdates
-
-        // Observe lastUpdateCheckDate via KVO
-        dateObservation = updater.observe(\.lastUpdateCheckDate, options: [.new]) { [weak self] _, change in
-            DispatchQueue.main.async {
-                self?.lastCheckDate = change.newValue ?? nil
-            }
-        }
+    convenience init() {
+        self.init(updater: ApplicationController.defaultInstance()?.updater)
+    }
+
+    init(updater: SPUUpdater?) {
+        self.updater = updater
+        self.lastCheckDate = updater?.lastUpdateCheckDate
+        self.automaticChecksEnabled = updater?.automaticallyChecksForUpdates ?? false
+
+        guard let updater else { return }
+
+        updater.publisher(for: \.canCheckForUpdates)
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$canCheckForUpdates)
+
+        updater.publisher(for: \.automaticallyChecksForUpdates)
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$automaticChecksEnabled)
+
+        updater.publisher(for: \.lastUpdateCheckDate)
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$lastCheckDate)
     }
 
-    /// Writes only to UserDefaults — SUUpdater observes this key via its own KVO.
     func setAutomaticChecks(_ enabled: Bool) {
-        automaticChecksEnabled = enabled
-        UserDefaults.standard.set(enabled, forKey: "SUEnableAutomaticChecks")
+        if let updater {
+            updater.automaticallyChecksForUpdates = enabled
+        } else {
+            automaticChecksEnabled = enabled
+        }
     }
 
     func checkForUpdates() {
-        SUUpdater.shared()?.checkForUpdates(nil)
+        guard let updater, updater.canCheckForUpdates else { return }
+        updater.checkForUpdates()
     }
 }
diff --git a/Tests/GasMaskTests/SparkleObserverTests.swift b/Tests/GasMaskTests/SparkleObserverTests.swift
index fd44774..a6c707d 100644
--- a/Tests/GasMaskTests/SparkleObserverTests.swift
+++ b/Tests/GasMaskTests/SparkleObserverTests.swift
@@ -4,13 +4,20 @@ import XCTest
 final class SparkleObserverTests: XCTestCase {
 
     func testLastCheckDateFormatted_nil_returnsNever() {
-        let observer = SparkleObserver()
+        let observer = SparkleObserver(updater: nil)
         observer.lastCheckDate = nil
         XCTAssertEqual(observer.lastCheckDateFormatted, "Last Checked: Never")
     }
 
+    func testNilUpdater_defaultState() {
+        let observer = SparkleObserver(updater: nil)
+        XCTAssertNil(observer.lastCheckDate)
+        XCTAssertFalse(observer.automaticChecksEnabled)
+        XCTAssertFalse(observer.canCheckForUpdates)
+    }
+
     func testLastCheckDateFormatted_date_returnsFormattedString() {
-        let observer = SparkleObserver()
+        let observer = SparkleObserver(updater: nil)
         // Use a fixed date: 2026-02-28 15:45:00 UTC
         var components = DateComponents()
         components.year = 2026