diff --git a/Sources/TerminalNotificationStore.swift b/Sources/TerminalNotificationStore.swift
index 35060ebe..e651a228 100644
--- a/Sources/TerminalNotificationStore.swift
+++ b/Sources/TerminalNotificationStore.swift
@@ -86,6 +86,24 @@ final class TerminalNotificationStore: ObservableObject {
     private var hasRequestedAuthorization = false
     private var hasPromptedForSettings = false
     private var userDefaultsObserver: NSObjectProtocol?
+    private let settingsPromptWindowRetryDelay: TimeInterval = 0.5
+    private let settingsPromptWindowRetryLimit = 20
+    private var notificationSettingsWindowProvider: () -> NSWindow? = {
+        NSApp.keyWindow ?? NSApp.mainWindow
+    }
+    private var notificationSettingsAlertFactory: () -> NSAlert = {
+        NSAlert()
+    }
+    private var notificationSettingsScheduler: (_ delay: TimeInterval, _ block: @escaping () -> Void) -> Void = {
+        delay,
+        block in
+        DispatchQueue.main.asyncAfter(deadline: .now() + delay) {
+            block()
+        }
+    }
+    private var notificationSettingsURLOpener: (URL) -> Void = { url in
+        NSWorkspace.shared.open(url)
+    }
 
     private init() {
         userDefaultsObserver = NotificationCenter.default.addObserver(
@@ -336,20 +354,71 @@ final class TerminalNotificationStore: ObservableObject {
         DispatchQueue.main.async { [weak self] in
             guard let self, !self.hasPromptedForSettings else { return }
             self.hasPromptedForSettings = true
-
-            let alert = NSAlert()
-            alert.messageText = "Enable Notifications for cmux"
-            alert.informativeText = "Notifications are disabled for cmux. Enable them in System Settings to see alerts."
-            alert.addButton(withTitle: "Open Settings")
-            alert.addButton(withTitle: "Not Now")
-            let response = alert.runModal()
-            guard response == .alertFirstButtonReturn else { return }
-            if let url = URL(string: "x-apple.systempreferences:com.apple.preference.notifications") {
-                NSWorkspace.shared.open(url)
-            }
+            self.presentNotificationSettingsPrompt(attempt: 0)
         }
     }
 
+    private func presentNotificationSettingsPrompt(attempt: Int) {
+        guard let window = notificationSettingsWindowProvider() else {
+            guard attempt < settingsPromptWindowRetryLimit else {
+                // If no window is available after retries, allow a future denied callback
+                // to prompt again when the app has a key/main window.
+                hasPromptedForSettings = false
+                return
+            }
+            notificationSettingsScheduler(settingsPromptWindowRetryDelay) { [weak self] in
+                self?.presentNotificationSettingsPrompt(attempt: attempt + 1)
+            }
+            return
+        }
+
+        let alert = notificationSettingsAlertFactory()
+        alert.messageText = "Enable Notifications for cmux"
+        alert.informativeText = "Notifications are disabled for cmux. Enable them in System Settings to see alerts."
+        alert.addButton(withTitle: "Open Settings")
+        alert.addButton(withTitle: "Not Now")
+        alert.beginSheetModal(for: window) { [weak self] response in
+            guard response == .alertFirstButtonReturn,
+                  let url = URL(string: "x-apple.systempreferences:com.apple.preference.notifications") else {
+                return
+            }
+            self?.notificationSettingsURLOpener(url)
+        }
+    }
+
+#if DEBUG
+    func configureNotificationSettingsPromptHooksForTesting(
+        windowProvider: @escaping () -> NSWindow?,
+        alertFactory: @escaping () -> NSAlert,
+        scheduler: @escaping (_ delay: TimeInterval, _ block: @escaping () -> Void) -> Void,
+        urlOpener: @escaping (URL) -> Void
+    ) {
+        notificationSettingsWindowProvider = windowProvider
+        notificationSettingsAlertFactory = alertFactory
+        notificationSettingsScheduler = scheduler
+        notificationSettingsURLOpener = urlOpener
+        hasPromptedForSettings = false
+    }
+
+    func resetNotificationSettingsPromptHooksForTesting() {
+        notificationSettingsWindowProvider = { NSApp.keyWindow ?? NSApp.mainWindow }
+        notificationSettingsAlertFactory = { NSAlert() }
+        notificationSettingsScheduler = { delay, block in
+            DispatchQueue.main.asyncAfter(deadline: .now() + delay) {
+                block()
+            }
+        }
+        notificationSettingsURLOpener = { url in
+            NSWorkspace.shared.open(url)
+        }
+        hasPromptedForSettings = false
+    }
+
+    func promptToEnableNotificationsForTesting() {
+        promptToEnableNotifications()
+    }
+#endif
+
     private func refreshDockBadge() {
         let label = Self.dockBadgeLabel(
             unreadCount: unreadCount,
diff --git a/cmuxTests/CmuxWebViewKeyEquivalentTests.swift b/cmuxTests/CmuxWebViewKeyEquivalentTests.swift
index ac345a9a..fe9c8431 100644
--- a/cmuxTests/CmuxWebViewKeyEquivalentTests.swift
+++ b/cmuxTests/CmuxWebViewKeyEquivalentTests.swift
@@ -5094,6 +5094,30 @@ final class OmnibarSuggestionRankingTests: XCTestCase {
 
 @MainActor
 final class NotificationDockBadgeTests: XCTestCase {
+    private final class NotificationSettingsAlertSpy: NSAlert {
+        private(set) var beginSheetModalCallCount = 0
+        private(set) var runModalCallCount = 0
+        var nextResponse: NSApplication.ModalResponse = .alertFirstButtonReturn
+
+        override func beginSheetModal(
+            for sheetWindow: NSWindow,
+            completionHandler handler: ((NSApplication.ModalResponse) -> Void)?
+        ) {
+            beginSheetModalCallCount += 1
+            handler?(nextResponse)
+        }
+
+        override func runModal() -> NSApplication.ModalResponse {
+            runModalCallCount += 1
+            return nextResponse
+        }
+    }
+
+    override func tearDown() {
+        TerminalNotificationStore.shared.resetNotificationSettingsPromptHooksForTesting()
+        super.tearDown()
+    }
+
     func testDockBadgeLabelEnabledAndCounted() {
         XCTAssertEqual(TerminalNotificationStore.dockBadgeLabel(unreadCount: 1, isEnabled: true), "1")
         XCTAssertEqual(TerminalNotificationStore.dockBadgeLabel(unreadCount: 42, isEnabled: true), "42")
@@ -5141,6 +5165,72 @@ final class NotificationDockBadgeTests: XCTestCase {
         defaults.set(true, forKey: NotificationBadgeSettings.dockBadgeEnabledKey)
         XCTAssertTrue(NotificationBadgeSettings.isDockBadgeEnabled(defaults: defaults))
     }
+
+    func testNotificationSettingsPromptUsesSheetAndNeverRunsModal() {
+        let store = TerminalNotificationStore.shared
+        let alertSpy = NotificationSettingsAlertSpy()
+        let window = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 480, height: 320),
+            styleMask: [.titled],
+            backing: .buffered,
+            defer: false
+        )
+
+        var openedURL: URL?
+        store.configureNotificationSettingsPromptHooksForTesting(
+            windowProvider: { window },
+            alertFactory: { alertSpy },
+            scheduler: { _, block in block() },
+            urlOpener: { openedURL = $0 }
+        )
+
+        store.promptToEnableNotificationsForTesting()
+        let drained = expectation(description: "main queue drained")
+        DispatchQueue.main.async { drained.fulfill() }
+        wait(for: [drained], timeout: 1.0)
+
+        XCTAssertEqual(alertSpy.beginSheetModalCallCount, 1)
+        XCTAssertEqual(alertSpy.runModalCallCount, 0)
+        XCTAssertEqual(
+            openedURL?.absoluteString,
+            "x-apple.systempreferences:com.apple.preference.notifications"
+        )
+    }
+
+    func testNotificationSettingsPromptRetriesUntilWindowExists() {
+        let store = TerminalNotificationStore.shared
+        let alertSpy = NotificationSettingsAlertSpy()
+        alertSpy.nextResponse = .alertSecondButtonReturn
+
+        var queuedRetryBlocks: [() -> Void] = []
+        var promptWindow: NSWindow?
+        store.configureNotificationSettingsPromptHooksForTesting(
+            windowProvider: { promptWindow },
+            alertFactory: { alertSpy },
+            scheduler: { _, block in queuedRetryBlocks.append(block) },
+            urlOpener: { _ in XCTFail("Should not open settings for Not Now response") }
+        )
+
+        store.promptToEnableNotificationsForTesting()
+        let drained = expectation(description: "main queue drained")
+        DispatchQueue.main.async { drained.fulfill() }
+        wait(for: [drained], timeout: 1.0)
+
+        XCTAssertEqual(alertSpy.beginSheetModalCallCount, 0)
+        XCTAssertEqual(alertSpy.runModalCallCount, 0)
+        XCTAssertEqual(queuedRetryBlocks.count, 1)
+
+        promptWindow = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 480, height: 320),
+            styleMask: [.titled],
+            backing: .buffered,
+            defer: false
+        )
+        queuedRetryBlocks.removeFirst()()
+
+        XCTAssertEqual(alertSpy.beginSheetModalCallCount, 1)
+        XCTAssertEqual(alertSpy.runModalCallCount, 0)
+    }
 }