diff --git a/Tests/OpenUsageTests/AntigravityLayoutTests.swift b/Tests/OpenUsageTests/AntigravityLayoutTests.swift
index f958c0a2d..b0d41b58a 100644
--- a/Tests/OpenUsageTests/AntigravityLayoutTests.swift
+++ b/Tests/OpenUsageTests/AntigravityLayoutTests.swift
@@ -101,10 +101,7 @@ final class AntigravityLayoutTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.AntigravityLayout.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.AntigravityLayout.\(name).\(UUID().uuidString)")
     }
 
     private func saveStored<T: Encodable>(_ value: T, forKey key: String, in defaults: UserDefaults) {
diff --git a/Tests/OpenUsageTests/CopilotProviderTests.swift b/Tests/OpenUsageTests/CopilotProviderTests.swift
index 540429999..841fbed0c 100644
--- a/Tests/OpenUsageTests/CopilotProviderTests.swift
+++ b/Tests/OpenUsageTests/CopilotProviderTests.swift
@@ -567,10 +567,7 @@ final class CopilotProviderTests: XCTestCase {
     }
 
     private func freshDefaults() -> UserDefaults {
-        let suiteName = "CopilotProviderTests-\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "CopilotProviderTests-\(UUID().uuidString)")
     }
 
     private func editorTokenStore() -> CopilotAuthStore {
diff --git a/Tests/OpenUsageTests/CursorSpendTests.swift b/Tests/OpenUsageTests/CursorSpendTests.swift
index 2ff582cd1..07ebaeb04 100644
--- a/Tests/OpenUsageTests/CursorSpendTests.swift
+++ b/Tests/OpenUsageTests/CursorSpendTests.swift
@@ -413,10 +413,7 @@ final class CursorSpendProviderTests: XCTestCase {
     // MARK: helpers
 
     private func isolatedDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.CursorSpend.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.CursorSpend.\(name).\(UUID().uuidString)")
     }
 
     private func isolatedCache(_ defaults: UserDefaults) -> ProviderSnapshotCache {
diff --git a/Tests/OpenUsageTests/FailureBackoffTests.swift b/Tests/OpenUsageTests/FailureBackoffTests.swift
index f1a1941fb..daf2c9e82 100644
--- a/Tests/OpenUsageTests/FailureBackoffTests.swift
+++ b/Tests/OpenUsageTests/FailureBackoffTests.swift
@@ -138,10 +138,7 @@ final class FailureBackoffTests: XCTestCase {
     }
 
     private func makeUserDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.Backoff.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.Backoff.\(name).\(UUID().uuidString)")
     }
 }
 
diff --git a/Tests/OpenUsageTests/FirstRunSeederTests.swift b/Tests/OpenUsageTests/FirstRunSeederTests.swift
index 6c04989b8..97027542d 100644
--- a/Tests/OpenUsageTests/FirstRunSeederTests.swift
+++ b/Tests/OpenUsageTests/FirstRunSeederTests.swift
@@ -181,10 +181,7 @@ final class FirstRunSeederTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.FirstRunSeeder.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.FirstRunSeeder.\(name).\(UUID().uuidString)")
     }
 }
 
diff --git a/Tests/OpenUsageTests/LayoutBootstrapTests.swift b/Tests/OpenUsageTests/LayoutBootstrapTests.swift
index fc4f91253..92772185c 100644
--- a/Tests/OpenUsageTests/LayoutBootstrapTests.swift
+++ b/Tests/OpenUsageTests/LayoutBootstrapTests.swift
@@ -66,8 +66,7 @@ final class LayoutBootstrapTests: XCTestCase {
 
     private func makePersistence(_ name: String) -> (LayoutPersistence, UserDefaults) {
         let suite = "OpenUsageTests.LayoutBootstrap.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suite)!
-        defaults.removePersistentDomain(forName: suite)
+        let defaults = makeScratchDefaults(suiteName: suite)
         return (LayoutPersistence(defaults: defaults, storageKey: "layout"), defaults)
     }
 }
diff --git a/Tests/OpenUsageTests/LayoutPersistenceTests.swift b/Tests/OpenUsageTests/LayoutPersistenceTests.swift
index afe1fff06..a79fcfd8e 100644
--- a/Tests/OpenUsageTests/LayoutPersistenceTests.swift
+++ b/Tests/OpenUsageTests/LayoutPersistenceTests.swift
@@ -67,9 +67,6 @@ final class LayoutPersistenceTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suite = "OpenUsageTests.LayoutPersistence.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suite)!
-        defaults.removePersistentDomain(forName: suite)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.LayoutPersistence.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/LayoutStoreTests.swift b/Tests/OpenUsageTests/LayoutStoreTests.swift
index def13e435..f56687369 100644
--- a/Tests/OpenUsageTests/LayoutStoreTests.swift
+++ b/Tests/OpenUsageTests/LayoutStoreTests.swift
@@ -1276,10 +1276,7 @@ final class LayoutStoreTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.LayoutStore.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.LayoutStore.\(name).\(UUID().uuidString)")
     }
 
     private func saveStored<T: Encodable>(_ value: T, forKey key: String, in defaults: UserDefaults) {
diff --git a/Tests/OpenUsageTests/LogLevelSettingTests.swift b/Tests/OpenUsageTests/LogLevelSettingTests.swift
index 460c850fd..f4da29375 100644
--- a/Tests/OpenUsageTests/LogLevelSettingTests.swift
+++ b/Tests/OpenUsageTests/LogLevelSettingTests.swift
@@ -57,9 +57,6 @@ final class LogLevelSettingTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.LogLevel.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.LogLevel.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/MenuBarPinTests.swift b/Tests/OpenUsageTests/MenuBarPinTests.swift
index e81585b25..569275d74 100644
--- a/Tests/OpenUsageTests/MenuBarPinTests.swift
+++ b/Tests/OpenUsageTests/MenuBarPinTests.swift
@@ -167,9 +167,6 @@ final class MenuBarPinTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.MenuBarPin.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.MenuBarPin.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/ModelUsageHoverTests.swift b/Tests/OpenUsageTests/ModelUsageHoverTests.swift
index d9d11b49b..eeffeffd9 100644
--- a/Tests/OpenUsageTests/ModelUsageHoverTests.swift
+++ b/Tests/OpenUsageTests/ModelUsageHoverTests.swift
@@ -181,9 +181,6 @@ final class ModelUsageHoverTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.ModelUsageHover.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.ModelUsageHover.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/NewProviderSeederTests.swift b/Tests/OpenUsageTests/NewProviderSeederTests.swift
index b3ae9b8de..c8323f656 100644
--- a/Tests/OpenUsageTests/NewProviderSeederTests.swift
+++ b/Tests/OpenUsageTests/NewProviderSeederTests.swift
@@ -116,10 +116,7 @@ final class NewProviderSeederTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.NewProviderSeeder.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.NewProviderSeeder.\(name).\(UUID().uuidString)")
     }
 }
 
diff --git a/Tests/OpenUsageTests/PopoverScreenTests.swift b/Tests/OpenUsageTests/PopoverScreenTests.swift
index 1322bbeb6..d6cf0aa45 100644
--- a/Tests/OpenUsageTests/PopoverScreenTests.swift
+++ b/Tests/OpenUsageTests/PopoverScreenTests.swift
@@ -41,9 +41,7 @@ final class PopoverScreenTests: XCTestCase {
     }
 
     private func makeStore(_ name: String) -> LayoutStore {
-        let suiteName = "OpenUsageTests.PopoverScreen.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
+        let defaults = makeScratchDefaults(suiteName: "OpenUsageTests.PopoverScreen.\(name).\(UUID().uuidString)")
         return LayoutStore(registry: .mock, defaults: defaults, storageKey: "layout")
     }
 }
diff --git a/Tests/OpenUsageTests/PopoverTransparencyStoreTests.swift b/Tests/OpenUsageTests/PopoverTransparencyStoreTests.swift
index 2c5164ffc..e874e4c4c 100644
--- a/Tests/OpenUsageTests/PopoverTransparencyStoreTests.swift
+++ b/Tests/OpenUsageTests/PopoverTransparencyStoreTests.swift
@@ -5,10 +5,7 @@ import XCTest
 final class PopoverTransparencyStoreTests: XCTestCase {
     /// Isolated, throwaway defaults per test (pattern from `RefreshSettingTests`).
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.Transparency.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.Transparency.\(name).\(UUID().uuidString)")
     }
 
     /// A store on throwaway defaults with the accessibility flags pinned (both off by default), so the
diff --git a/Tests/OpenUsageTests/ProviderEnablementEnforcementTests.swift b/Tests/OpenUsageTests/ProviderEnablementEnforcementTests.swift
index 7ab2f618b..29840390f 100644
--- a/Tests/OpenUsageTests/ProviderEnablementEnforcementTests.swift
+++ b/Tests/OpenUsageTests/ProviderEnablementEnforcementTests.swift
@@ -106,9 +106,6 @@ final class ProviderEnablementEnforcementTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.EnablementEnforce.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.EnablementEnforce.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/ProviderEnablementStoreTests.swift b/Tests/OpenUsageTests/ProviderEnablementStoreTests.swift
index 89c29eb2f..f4d1865c7 100644
--- a/Tests/OpenUsageTests/ProviderEnablementStoreTests.swift
+++ b/Tests/OpenUsageTests/ProviderEnablementStoreTests.swift
@@ -178,9 +178,6 @@ final class ProviderEnablementStoreTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.Enablement.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.Enablement.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/RefreshSettingTests.swift b/Tests/OpenUsageTests/RefreshSettingTests.swift
index 3e1e0f60b..fdcf6aec7 100644
--- a/Tests/OpenUsageTests/RefreshSettingTests.swift
+++ b/Tests/OpenUsageTests/RefreshSettingTests.swift
@@ -121,9 +121,6 @@ final class RefreshSettingTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.RefreshSetting.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.RefreshSetting.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/StaleWhileRevalidateTests.swift b/Tests/OpenUsageTests/StaleWhileRevalidateTests.swift
index f40970556..2e4d63d65 100644
--- a/Tests/OpenUsageTests/StaleWhileRevalidateTests.swift
+++ b/Tests/OpenUsageTests/StaleWhileRevalidateTests.swift
@@ -199,10 +199,7 @@ final class StaleWhileRevalidateTests: XCTestCase {
     }
 
     private func makeUserDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.StaleWhileRevalidate.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.StaleWhileRevalidate.\(name).\(UUID().uuidString)")
     }
 }
 
diff --git a/Tests/OpenUsageTests/StalenessLabelTests.swift b/Tests/OpenUsageTests/StalenessLabelTests.swift
index 9d275ca03..3499bfff6 100644
--- a/Tests/OpenUsageTests/StalenessLabelTests.swift
+++ b/Tests/OpenUsageTests/StalenessLabelTests.swift
@@ -121,9 +121,7 @@ final class StalenessLabelTests: XCTestCase {
         descriptor: WidgetDescriptor,
         runtime: some ProviderRuntime
     ) -> WidgetDataStore {
-        let suiteName = "OpenUsageTests.Staleness.\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
+        let defaults = makeScratchDefaults(suiteName: "OpenUsageTests.Staleness.\(UUID().uuidString)")
         return WidgetDataStore(
             registry: WidgetRegistry(providers: [provider], descriptors: [descriptor]),
             providers: [runtime],
diff --git a/Tests/OpenUsageTests/TelemetryRecorderTests.swift b/Tests/OpenUsageTests/TelemetryRecorderTests.swift
index a4f40ee88..bdcb73790 100644
--- a/Tests/OpenUsageTests/TelemetryRecorderTests.swift
+++ b/Tests/OpenUsageTests/TelemetryRecorderTests.swift
@@ -151,9 +151,6 @@ final class TelemetryRecorderTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.Telemetry.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.Telemetry.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/TestSupport.swift b/Tests/OpenUsageTests/TestSupport.swift
index 58fc44962..290495cdf 100644
--- a/Tests/OpenUsageTests/TestSupport.swift
+++ b/Tests/OpenUsageTests/TestSupport.swift
@@ -1,6 +1,20 @@
 import XCTest
 @testable import OpenUsage
 
+extension XCTestCase {
+    /// A `UserDefaults` backed by a throwaway suite that is cleared *now* (so the test starts from a
+    /// clean slate) and whose persistent domain is removed again in this test's teardown. Use this for
+    /// any test needing an isolated defaults store: it prevents test data from lingering after the
+    /// run. Pass a unique `suiteName` (embed a `UUID()`) so parallel or repeated tests don't collide.
+    /// macOS 27 may still recreate an empty plist shell for a suite when the test process exits.
+    func makeScratchDefaults(suiteName: String) -> UserDefaults {
+        let defaults = UserDefaults(suiteName: suiteName)!
+        defaults.removePersistentDomain(forName: suiteName) // clean slate at start
+        addTeardownBlock { UserDefaults().removePersistentDomain(forName: suiteName) }
+        return defaults
+    }
+}
+
 /// The shipped pricing resources (supplement + LiteLLM/models.dev snapshots) as a ready-to-use
 /// `ModelPricing` — loaded once, entirely offline (no store, no network, no disk cache). Tests that
 /// price real model names use this the way production code uses `ModelPricingStore.current()`.
diff --git a/Tests/OpenUsageTests/UsageTrendTests.swift b/Tests/OpenUsageTests/UsageTrendTests.swift
index a325b8a53..72e600e97 100644
--- a/Tests/OpenUsageTests/UsageTrendTests.swift
+++ b/Tests/OpenUsageTests/UsageTrendTests.swift
@@ -210,9 +210,6 @@ final class UsageTrendTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.Trend.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.Trend.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/WidgetDataStoreNotificationTests.swift b/Tests/OpenUsageTests/WidgetDataStoreNotificationTests.swift
index 7dbab68d4..5dbbe72a7 100644
--- a/Tests/OpenUsageTests/WidgetDataStoreNotificationTests.swift
+++ b/Tests/OpenUsageTests/WidgetDataStoreNotificationTests.swift
@@ -39,10 +39,7 @@ final class WidgetDataStoreNotificationTests: XCTestCase {
     }
 
     private func makeUserDefaults(_ name: String) -> UserDefaults {
-        let suite = "WidgetDataStoreNotificationTests.\(name)"
-        let defaults = UserDefaults(suiteName: suite)!
-        defaults.removePersistentDomain(forName: suite)
-        return defaults
+        makeScratchDefaults(suiteName: "WidgetDataStoreNotificationTests.\(name)")
     }
 
     private static let provider = Provider(id: "test", displayName: "Test", icon: .providerMark("cursor"))
diff --git a/Tests/OpenUsageTests/WidgetDataStorePlanTests.swift b/Tests/OpenUsageTests/WidgetDataStorePlanTests.swift
index db442aec8..40f8431fb 100644
--- a/Tests/OpenUsageTests/WidgetDataStorePlanTests.swift
+++ b/Tests/OpenUsageTests/WidgetDataStorePlanTests.swift
@@ -101,9 +101,6 @@ final class WidgetDataStorePlanTests: XCTestCase {
     }
 
     private func makeDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.Plan.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.Plan.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/WidgetDataStoreTests.swift b/Tests/OpenUsageTests/WidgetDataStoreTests.swift
index 16c7b80c3..35fefb433 100644
--- a/Tests/OpenUsageTests/WidgetDataStoreTests.swift
+++ b/Tests/OpenUsageTests/WidgetDataStoreTests.swift
@@ -739,9 +739,6 @@ final class WidgetDataStoreTests: XCTestCase {
     }
 
     private func makeUserDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/WidgetMeterStyleTests.swift b/Tests/OpenUsageTests/WidgetMeterStyleTests.swift
index e16285bf0..a991145fc 100644
--- a/Tests/OpenUsageTests/WidgetMeterStyleTests.swift
+++ b/Tests/OpenUsageTests/WidgetMeterStyleTests.swift
@@ -179,10 +179,7 @@ final class WidgetMeterStyleTests: XCTestCase {
     }
 
     func testMeterStylePersistsAcrossStoreInstances() {
-        let suiteName = "OpenUsageTests.MeterStyle.persist.\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        defer { defaults.removePersistentDomain(forName: suiteName) }
+        let defaults = makeScratchDefaults(suiteName: "OpenUsageTests.MeterStyle.persist.\(UUID().uuidString)")
 
         let store = makeEmptyStore(defaults)
         XCTAssertEqual(store.meterStyle, .remaining)
@@ -268,9 +265,6 @@ final class WidgetMeterStyleTests: XCTestCase {
     }
 
     private func makeUserDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.MeterStyle.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.MeterStyle.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/WidgetNoDataTests.swift b/Tests/OpenUsageTests/WidgetNoDataTests.swift
index d875da7c9..67ca7ae25 100644
--- a/Tests/OpenUsageTests/WidgetNoDataTests.swift
+++ b/Tests/OpenUsageTests/WidgetNoDataTests.swift
@@ -93,9 +93,6 @@ final class WidgetNoDataTests: XCTestCase {
     }
 
     private func makeUserDefaults(_ name: String) -> UserDefaults {
-        let suiteName = "OpenUsageTests.NoData.\(name).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
-        return defaults
+        makeScratchDefaults(suiteName: "OpenUsageTests.NoData.\(name).\(UUID().uuidString)")
     }
 }
diff --git a/Tests/OpenUsageTests/WidgetPercentClampTests.swift b/Tests/OpenUsageTests/WidgetPercentClampTests.swift
index 476f339ce..d0900ff97 100644
--- a/Tests/OpenUsageTests/WidgetPercentClampTests.swift
+++ b/Tests/OpenUsageTests/WidgetPercentClampTests.swift
@@ -69,9 +69,7 @@ final class WidgetPercentClampTests: XCTestCase {
                 lines: [.progress(label: "Metric", used: used, limit: 100, format: .percent)]
             )
         )
-        let suiteName = "OpenUsageTests.PercentClamp.\(suite).\(UUID().uuidString)"
-        let defaults = UserDefaults(suiteName: suiteName)!
-        defaults.removePersistentDomain(forName: suiteName)
+        let defaults = makeScratchDefaults(suiteName: "OpenUsageTests.PercentClamp.\(suite).\(UUID().uuidString)")
         let cache = ProviderSnapshotCache(userDefaults: defaults, storageKey: "snapshots", ttl: 600, now: { Date() })
         let store = WidgetDataStore(
             registry: WidgetRegistry(providers: [provider], descriptors: [descriptor]),