diff --git a/Sources/Update/UpdatePill.swift b/Sources/Update/UpdatePill.swift
index 25f163b2..6f27061d 100644
--- a/Sources/Update/UpdatePill.swift
+++ b/Sources/Update/UpdatePill.swift
@@ -1,5 +1,4 @@
 import AppKit
-import Bonsplit
 import Foundation
 import SwiftUI
 
@@ -13,12 +12,11 @@ struct UpdatePill: View {
     var body: some View {
         if model.showsPill {
             pillButton
-                .popover(
-                    isPresented: $showPopover,
-                    attachmentAnchor: .rect(.bounds),
-                    arrowEdge: .top
-                ) {
-                    UpdatePopoverView(model: model)
+                .background(UpdatePillPopoverAnchor(isPresented: $showPopover, model: model))
+                .onChange(of: model.showsPill) { _, showsPill in
+                    if !showsPill {
+                        showPopover = false
+                    }
                 }
                 .transition(.opacity.combined(with: .scale(scale: 0.95)))
         }
@@ -26,23 +24,7 @@ struct UpdatePill: View {
 
     @ViewBuilder
     private var pillButton: some View {
-        Button(action: {
-            if model.showsDetectedBackgroundUpdate {
-                if showPopover {
-                    showPopover = false
-                } else {
-                    showPopover = true
-                    AppDelegate.shared?.checkForUpdatesInCustomUI()
-                }
-                return
-            }
-            if case .notFound(let notFound) = model.state {
-                model.state = .idle
-                notFound.acknowledgement()
-            } else {
-                showPopover.toggle()
-            }
-        }) {
+        Button(action: handleTap) {
             HStack(spacing: 6) {
                 UpdateBadge(model: model)
                     .frame(width: 14, height: 14)
@@ -68,6 +50,27 @@ struct UpdatePill: View {
         .accessibilityIdentifier("UpdatePill")
     }
 
+    private func handleTap() {
+        if model.showsDetectedBackgroundUpdate {
+            if model.hasCachedDetectedUpdateDetails {
+                showPopover.toggle()
+            } else if showPopover {
+                showPopover = false
+            } else {
+                showPopover = true
+                AppDelegate.shared?.checkForUpdatesInCustomUI()
+            }
+            return
+        }
+
+        if case .notFound(let notFound) = model.state {
+            model.state = .idle
+            notFound.acknowledgement()
+        } else {
+            showPopover.toggle()
+        }
+    }
+
     private var textWidth: CGFloat? {
         let attributes: [NSAttributedString.Key: Any] = [.font: textFont]
         let size = (model.maxWidthText as NSString).size(withAttributes: attributes)
@@ -75,6 +78,113 @@ struct UpdatePill: View {
     }
 }
 
+private struct UpdatePillPopoverAnchor: NSViewRepresentable {
+    @Binding var isPresented: Bool
+    @ObservedObject var model: UpdateViewModel
+
+    func makeNSView(context: Context) -> NSView {
+        let view = NSView()
+        context.coordinator.anchorView = view
+        return view
+    }
+
+    func updateNSView(_ nsView: NSView, context: Context) {
+        let coordinator = context.coordinator
+        context.coordinator.anchorView = nsView
+        context.coordinator.updateRootView(
+            AnyView(
+                UpdatePopoverView(model: model) {
+                    [weak coordinator] in
+                    coordinator?.closeFromContent()
+                }
+            )
+        )
+
+        if isPresented {
+            context.coordinator.present()
+        } else {
+            context.coordinator.dismiss()
+        }
+    }
+
+    func makeCoordinator() -> Coordinator {
+        Coordinator(isPresented: $isPresented)
+    }
+
+    static func dismantleNSView(_ nsView: NSView, coordinator: Coordinator) {
+        coordinator.dismiss()
+    }
+
+    final class Coordinator: NSObject, NSPopoverDelegate {
+        @Binding var isPresented: Bool
+
+        weak var anchorView: NSView?
+        private let hostingController = NSHostingController(rootView: AnyView(EmptyView()))
+        private var popover: NSPopover?
+
+        init(isPresented: Binding<Bool>) {
+            _isPresented = isPresented
+        }
+
+        func updateRootView(_ rootView: AnyView) {
+            hostingController.rootView = rootView
+            hostingController.view.invalidateIntrinsicContentSize()
+            hostingController.view.layoutSubtreeIfNeeded()
+            updateContentSize()
+        }
+
+        func present() {
+            guard let anchorView, anchorView.window != nil else {
+                isPresented = false
+                dismiss()
+                return
+            }
+
+            anchorView.superview?.layoutSubtreeIfNeeded()
+            let popover = popover ?? makePopover()
+            updateContentSize()
+            guard !popover.isShown else { return }
+
+            popover.show(relativeTo: anchorView.bounds, of: anchorView, preferredEdge: .maxY)
+        }
+
+        func dismiss() {
+            popover?.performClose(nil)
+        }
+
+        func closeFromContent() {
+            isPresented = false
+            dismiss()
+        }
+
+        func popoverDidClose(_ notification: Notification) {
+            popover = nil
+            if isPresented {
+                isPresented = false
+            }
+        }
+
+        private func makePopover() -> NSPopover {
+            let popover = NSPopover()
+            popover.behavior = .semitransient
+            popover.animates = true
+            popover.contentViewController = hostingController
+            popover.delegate = self
+            self.popover = popover
+            return popover
+        }
+
+        private func updateContentSize() {
+            let fittingSize = hostingController.view.fittingSize
+            guard fittingSize.width > 0, fittingSize.height > 0 else { return }
+            popover?.contentSize = NSSize(
+                width: ceil(fittingSize.width),
+                height: ceil(fittingSize.height)
+            )
+        }
+    }
+}
+
 /// Menu item that shows "Install Update and Relaunch" when an update is ready.
 struct InstallUpdateMenuItem: View {
     @ObservedObject var model: UpdateViewModel
diff --git a/Sources/Update/UpdatePopoverView.swift b/Sources/Update/UpdatePopoverView.swift
index 301c3ae1..88c249f7 100644
--- a/Sources/Update/UpdatePopoverView.swift
+++ b/Sources/Update/UpdatePopoverView.swift
@@ -1,19 +1,27 @@
 import AppKit
-import SwiftUI
 import Sparkle
+import SwiftUI
 
 /// Popover view that displays detailed update information and actions.
 struct UpdatePopoverView: View {
     @ObservedObject var model: UpdateViewModel
-    @Environment(\.dismiss) private var dismiss
+    let dismiss: () -> Void
+
+    init(model: UpdateViewModel, dismiss: @escaping () -> Void = {}) {
+        self.model = model
+        self.dismiss = dismiss
+    }
 
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {
             switch model.effectiveState {
             case .idle:
-                if let detectedVersion = model.detectedUpdateVersion,
-                   model.showsDetectedBackgroundUpdate {
-                    DetectedBackgroundUpdateView(version: detectedVersion)
+                if model.showsDetectedBackgroundUpdate,
+                   let detectedItem = model.detectedUpdateItem {
+                    DetectedBackgroundUpdateView(item: detectedItem, dismiss: dismiss)
+                } else if let detectedVersion = model.detectedUpdateVersion,
+                          model.showsDetectedBackgroundUpdate {
+                    DetectedBackgroundUpdatePendingView(version: detectedVersion)
                 } else {
                     EmptyView()
                 }
@@ -47,7 +55,113 @@ struct UpdatePopoverView: View {
     }
 }
 
+fileprivate struct UpdateMetadataView: View {
+    let item: SUAppcastItem
+    let labelWidth: CGFloat
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 4) {
+            HStack(spacing: 6) {
+                Text(String(localized: "update.popover.version", defaultValue: "Version:"))
+                    .foregroundColor(.secondary)
+                    .frame(width: labelWidth, alignment: .trailing)
+                Text(item.displayVersionString)
+            }
+            .font(.system(size: 11))
+
+            if item.contentLength > 0 {
+                HStack(spacing: 6) {
+                    Text(String(localized: "update.popover.size", defaultValue: "Size:"))
+                        .foregroundColor(.secondary)
+                        .frame(width: labelWidth, alignment: .trailing)
+                    Text(ByteCountFormatter.string(fromByteCount: Int64(item.contentLength), countStyle: .file))
+                }
+                .font(.system(size: 11))
+            }
+
+            if let date = item.date {
+                HStack(spacing: 6) {
+                    Text(String(localized: "update.popover.released", defaultValue: "Released:"))
+                        .foregroundColor(.secondary)
+                        .frame(width: labelWidth, alignment: .trailing)
+                    Text(date.formatted(date: .abbreviated, time: .omitted))
+                }
+                .font(.system(size: 11))
+            }
+        }
+        .textSelection(.enabled)
+    }
+}
+
+fileprivate struct UpdateReleaseNotesLink: View {
+    let notes: UpdateState.ReleaseNotes
+
+    var body: some View {
+        Link(destination: notes.url) {
+            HStack {
+                Image(systemName: "doc.text")
+                    .font(.system(size: 11))
+                Text(notes.label)
+                    .font(.system(size: 11, weight: .medium))
+                Spacer()
+                Image(systemName: "arrow.up.right")
+                    .font(.system(size: 10))
+            }
+            .foregroundColor(.primary)
+            .padding(12)
+            .frame(maxWidth: .infinity)
+            .background(Color(nsColor: .controlBackgroundColor))
+            .contentShape(Rectangle())
+        }
+        .buttonStyle(.plain)
+    }
+}
+
 fileprivate struct DetectedBackgroundUpdateView: View {
+    let item: SUAppcastItem
+    let dismiss: () -> Void
+
+    private let labelWidth: CGFloat = 60
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 0) {
+            VStack(alignment: .leading, spacing: 12) {
+                VStack(alignment: .leading, spacing: 8) {
+                    Text(String(localized: "update.popover.updateAvailable", defaultValue: "Update Available"))
+                        .font(.system(size: 13, weight: .semibold))
+
+                    UpdateMetadataView(item: item, labelWidth: labelWidth)
+                }
+
+                HStack(spacing: 8) {
+                    Button(String(localized: "common.later", defaultValue: "Later")) {
+                        dismiss()
+                    }
+                    .controlSize(.small)
+                    .keyboardShortcut(.cancelAction)
+
+                    Spacer()
+
+                    Button(String(localized: "common.installAndRelaunch", defaultValue: "Install and Relaunch")) {
+                        AppDelegate.shared?.attemptUpdate(nil)
+                        dismiss()
+                    }
+                    .keyboardShortcut(.defaultAction)
+                    .buttonStyle(.borderedProminent)
+                    .controlSize(.small)
+                }
+            }
+            .padding(16)
+
+            if let notes = UpdateState.ReleaseNotes(displayVersionString: item.displayVersionString) {
+                Divider()
+                UpdateReleaseNotesLink(notes: notes)
+            }
+        }
+    }
+}
+
+fileprivate struct DetectedBackgroundUpdatePendingView: View {
     let version: String
 
     var body: some View {
@@ -78,7 +192,7 @@ fileprivate struct DetectedBackgroundUpdateView: View {
 
 fileprivate struct PermissionRequestView: View {
     let request: UpdateState.PermissionRequest
-    let dismiss: DismissAction
+    let dismiss: () -> Void
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
@@ -96,7 +210,8 @@ fileprivate struct PermissionRequestView: View {
                 Button(String(localized: "common.notNow", defaultValue: "Not Now")) {
                     request.reply(SUUpdatePermissionResponse(
                         automaticUpdateChecks: false,
-                        sendSystemProfile: false))
+                        sendSystemProfile: false
+                    ))
                     dismiss()
                 }
                 .keyboardShortcut(.cancelAction)
@@ -106,7 +221,8 @@ fileprivate struct PermissionRequestView: View {
                 Button(String(localized: "common.allow", defaultValue: "Allow")) {
                     request.reply(SUUpdatePermissionResponse(
                         automaticUpdateChecks: true,
-                        sendSystemProfile: false))
+                        sendSystemProfile: false
+                    ))
                     dismiss()
                 }
                 .keyboardShortcut(.defaultAction)
@@ -119,7 +235,7 @@ fileprivate struct PermissionRequestView: View {
 
 fileprivate struct CheckingView: View {
     let checking: UpdateState.Checking
-    let dismiss: DismissAction
+    let dismiss: () -> Void
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
@@ -146,7 +262,7 @@ fileprivate struct CheckingView: View {
 
 fileprivate struct UpdateAvailableView: View {
     let update: UpdateState.UpdateAvailable
-    let dismiss: DismissAction
+    let dismiss: () -> Void
 
     private let labelWidth: CGFloat = 60
 
@@ -157,36 +273,7 @@ fileprivate struct UpdateAvailableView: View {
                     Text(String(localized: "update.popover.updateAvailable", defaultValue: "Update Available"))
                         .font(.system(size: 13, weight: .semibold))
 
-                    VStack(alignment: .leading, spacing: 4) {
-                        HStack(spacing: 6) {
-                            Text(String(localized: "update.popover.version", defaultValue: "Version:"))
-                                .foregroundColor(.secondary)
-                                .frame(width: labelWidth, alignment: .trailing)
-                            Text(update.appcastItem.displayVersionString)
-                        }
-                        .font(.system(size: 11))
-
-                        if update.appcastItem.contentLength > 0 {
-                            HStack(spacing: 6) {
-                                Text(String(localized: "update.popover.size", defaultValue: "Size:"))
-                                    .foregroundColor(.secondary)
-                                    .frame(width: labelWidth, alignment: .trailing)
-                                Text(ByteCountFormatter.string(fromByteCount: Int64(update.appcastItem.contentLength), countStyle: .file))
-                            }
-                            .font(.system(size: 11))
-                        }
-
-                        if let date = update.appcastItem.date {
-                            HStack(spacing: 6) {
-                                Text(String(localized: "update.popover.released", defaultValue: "Released:"))
-                                    .foregroundColor(.secondary)
-                                    .frame(width: labelWidth, alignment: .trailing)
-                                Text(date.formatted(date: .abbreviated, time: .omitted))
-                            }
-                            .font(.system(size: 11))
-                        }
-                    }
-                    .textSelection(.enabled)
+                    UpdateMetadataView(item: update.appcastItem, labelWidth: labelWidth)
                 }
 
                 HStack(spacing: 8) {
@@ -218,24 +305,7 @@ fileprivate struct UpdateAvailableView: View {
 
             if let notes = update.releaseNotes {
                 Divider()
-
-                Link(destination: notes.url) {
-                    HStack {
-                        Image(systemName: "doc.text")
-                            .font(.system(size: 11))
-                        Text(notes.label)
-                            .font(.system(size: 11, weight: .medium))
-                        Spacer()
-                        Image(systemName: "arrow.up.right")
-                            .font(.system(size: 10))
-                    }
-                    .foregroundColor(.primary)
-                    .padding(12)
-                    .frame(maxWidth: .infinity)
-                    .background(Color(nsColor: .controlBackgroundColor))
-                    .contentShape(Rectangle())
-                }
-                .buttonStyle(.plain)
+                UpdateReleaseNotesLink(notes: notes)
             }
         }
     }
@@ -243,7 +313,7 @@ fileprivate struct UpdateAvailableView: View {
 
 fileprivate struct DownloadingView: View {
     let download: UpdateState.Downloading
-    let dismiss: DismissAction
+    let dismiss: () -> Void
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
@@ -300,7 +370,7 @@ fileprivate struct ExtractingView: View {
 
 fileprivate struct InstallingView: View {
     let installing: UpdateState.Installing
-    let dismiss: DismissAction
+    let dismiss: () -> Void
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
@@ -339,7 +409,7 @@ fileprivate struct InstallingView: View {
 
 fileprivate struct NotFoundView: View {
     let notFound: UpdateState.NotFound
-    let dismiss: DismissAction
+    let dismiss: () -> Void
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
@@ -369,7 +439,7 @@ fileprivate struct NotFoundView: View {
 
 fileprivate struct UpdateErrorView: View {
     let error: UpdateState.Error
-    let dismiss: DismissAction
+    let dismiss: () -> Void
 
     var body: some View {
         let title = UpdateViewModel.userFacingErrorTitle(for: error.error)
diff --git a/Sources/Update/UpdateTestSupport.swift b/Sources/Update/UpdateTestSupport.swift
index 77535482..872f2ac3 100644
--- a/Sources/Update/UpdateTestSupport.swift
+++ b/Sources/Update/UpdateTestSupport.swift
@@ -10,7 +10,11 @@ enum UpdateTestSupport {
         if let detectedVersion = env["CMUX_UI_TEST_DETECTED_UPDATE_VERSION"],
            !detectedVersion.isEmpty {
             DispatchQueue.main.async {
-                viewModel.detectedUpdateVersion = UpdateViewModel.normalizedDetectedUpdateVersion(from: detectedVersion)
+                if let item = makeAppcastItem(displayVersion: detectedVersion) {
+                    viewModel.recordDetectedUpdate(item)
+                } else {
+                    viewModel.detectedUpdateVersion = UpdateViewModel.normalizedDetectedUpdateVersion(from: detectedVersion)
+                }
             }
         }
 
@@ -87,6 +91,7 @@ enum UpdateTestSupport {
         ]
         let dict: [String: Any] = [
             "title": "cmux \(displayVersion)",
+            "pubDate": "Wed, 25 Mar 2026 12:00:00 +0000",
             "enclosure": enclosure,
         ]
         return SUAppcastItem(dictionary: dict)
diff --git a/Sources/Update/UpdateViewModel.swift b/Sources/Update/UpdateViewModel.swift
index 93b4b799..2789cc05 100644
--- a/Sources/Update/UpdateViewModel.swift
+++ b/Sources/Update/UpdateViewModel.swift
@@ -7,6 +7,7 @@ class UpdateViewModel: ObservableObject {
     @Published var state: UpdateState = .idle
     @Published var overrideState: UpdateState?
     @Published var detectedUpdateVersion: String?
+    @Published private(set) var detectedUpdateItem: SUAppcastItem?
     #if DEBUG
     @Published var debugOverrideText: String?
     #endif
@@ -19,15 +20,22 @@ class UpdateViewModel: ObservableObject {
         effectiveState.isIdle && detectedUpdateVersion != nil
     }
 
+    var hasCachedDetectedUpdateDetails: Bool {
+        detectedUpdateItem != nil
+    }
+
     var showsPill: Bool {
         !effectiveState.isIdle || showsDetectedBackgroundUpdate
     }
 
     func recordDetectedUpdate(_ item: SUAppcastItem) {
-        detectedUpdateVersion = Self.normalizedDetectedUpdateVersion(from: item.displayVersionString)
+        let version = Self.normalizedDetectedUpdateVersion(from: item.displayVersionString)
+        detectedUpdateItem = version == nil ? nil : item
+        detectedUpdateVersion = version
     }
 
     func clearDetectedUpdate() {
+        detectedUpdateItem = nil
         detectedUpdateVersion = nil
     }
 
diff --git a/cmuxUITests/UpdatePillUITests.swift b/cmuxUITests/UpdatePillUITests.swift
index 8493a0de..75544bdc 100644
--- a/cmuxUITests/UpdatePillUITests.swift
+++ b/cmuxUITests/UpdatePillUITests.swift
@@ -67,9 +67,7 @@ final class UpdatePillUITests: XCTestCase {
         app.launchEnvironment["CMUX_UI_TEST_MODE"] = "1"
         app.launchEnvironment["CMUX_UI_TEST_DETECTED_UPDATE_VERSION"] = "9.9.9"
         app.launchEnvironment["CMUX_UI_TEST_FEED_URL"] = "https://cmux.test/appcast.xml"
-        app.launchEnvironment["CMUX_UI_TEST_FEED_MODE"] = "available"
-        app.launchEnvironment["CMUX_UI_TEST_UPDATE_VERSION"] = "9.9.9"
-        app.launchEnvironment["CMUX_UI_TEST_AUTO_ALLOW_PERMISSION"] = "1"
+        app.launchEnvironment["CMUX_UI_TEST_FEED_MODE"] = "none"
         launchAndActivate(app)
 
         let pill = pillButton(app: app, expectedLabel: "Update Available: 9.9.9")
@@ -82,7 +80,10 @@ final class UpdatePillUITests: XCTestCase {
             app.staticTexts["Update Available"].waitForExistence(timeout: 8.0),
             "Expected the first click on a background-detected update pill to open the popover"
         )
-        XCTAssertTrue(app.buttons["Install and Relaunch"].waitForExistence(timeout: 2.0))
+        XCTAssertTrue(
+            app.buttons["Install and Relaunch"].waitForExistence(timeout: 2.0),
+            "Expected cached update info to show the install action without running a new update check"
+        )
     }
 
     func testUpdatePillShowsForNoUpdateThenDismisses() {