diff --git a/Normal/Services/KeychainItem.swift b/Normal/Services/KeychainItem.swift
index 8410113..e486ff7 100644
--- a/Normal/Services/KeychainItem.swift
+++ b/Normal/Services/KeychainItem.swift
@@ -1,11 +1,17 @@
 import Foundation
 import Security
 
+nonisolated protocol KeychainStoring: Sendable {
+    func loadData() -> Data?
+    func saveData(_ data: Data)
+    func delete()
+}
+
 /// A single generic-password slot in the Keychain.
 ///
 /// Used for counters that must survive a delete-and-reinstall — the whole point
 /// of storing them outside the app container.
-struct KeychainItem: Sendable {
+struct KeychainItem: KeychainStoring {
     let service: String
     let account: String
 
@@ -43,7 +49,7 @@ struct KeychainItem: Sendable {
     }
 }
 
-extension KeychainItem {
+extension KeychainStoring {
     func load<T: Decodable>(_ type: T.Type) -> T? {
         guard let data = loadData() else { return nil }
         return try? PropertyListDecoder().decode(type, from: data)
diff --git a/Normal/Services/UsageLimitLedger.swift b/Normal/Services/UsageLimitLedger.swift
index eb295fe..78b60a7 100644
--- a/Normal/Services/UsageLimitLedger.swift
+++ b/Normal/Services/UsageLimitLedger.swift
@@ -10,13 +10,15 @@ struct KeychainUsageLimitLedger: UsageLimitLedger {
         let lastLoosened: Date
     }
 
-    private let item: KeychainItem
+    private let item: any KeychainStoring
 
     init(
-        service: String = "com.normalengineering.normal.usageLimits",
-        account: String = "lastLoosened"
+        item: any KeychainStoring = KeychainItem(
+            service: "com.normalengineering.normal.usageLimits",
+            account: "lastLoosened"
+        )
     ) {
-        item = KeychainItem(service: service, account: account)
+        self.item = item
     }
 
     func loadLastLoosened() -> Date? {
diff --git a/NormalTests/Services/UsageLimitServiceTests.swift b/NormalTests/Services/UsageLimitServiceTests.swift
index 9edd22a..185471c 100644
--- a/NormalTests/Services/UsageLimitServiceTests.swift
+++ b/NormalTests/Services/UsageLimitServiceTests.swift
@@ -429,18 +429,34 @@ struct UsageLimitServiceTests {
     }
 
     @Test func theKeychainLedgerSurvivesARelaunch() {
-        let service = "com.normalengineering.normal.tests.\(UUID().uuidString)"
+        let item = InMemoryKeychainItem()
         let stored = Date(timeIntervalSinceReferenceDate: 500_000)
-        KeychainUsageLimitLedger(service: service).saveLastLoosened(stored)
-        defer { KeychainUsageLimitLedger(service: service).saveLastLoosened(nil) }
+        KeychainUsageLimitLedger(item: item).saveLastLoosened(stored)
 
         let relaunched = UsageLimitService(
             activityCenter: FakeDeviceActivityCenter(),
             sharedStore: FakeSharedStore(),
-            ledger: KeychainUsageLimitLedger(service: service),
+            ledger: KeychainUsageLimitLedger(item: item),
             limitShield: InMemoryDailyLimitShield()
         )
 
         #expect(relaunched.decideResetChange(now: stored + .days(2)) == .locked(until: stored + .days(7)))
     }
 }
+
+private final class InMemoryKeychainItem: KeychainStoring, @unchecked Sendable {
+    private let lock = NSLock()
+    private var data: Data?
+
+    func loadData() -> Data? {
+        lock.withLock { data }
+    }
+
+    func saveData(_ data: Data) {
+        lock.withLock { self.data = data }
+    }
+
+    func delete() {
+        lock.withLock { data = nil }
+    }
+}