diff --git a/CableTests/LocalizationIntegrityTests.swift b/CableTests/LocalizationIntegrityTests.swift
new file mode 100644
index 0000000..d9c48f3
--- /dev/null
+++ b/CableTests/LocalizationIntegrityTests.swift
@@ -0,0 +1,75 @@
+import Foundation
+import Testing
+@testable import Cable
+
+/// Guards the string tables themselves. A malformed `.strings` file still parses — a value
+/// spanning several lines silently swallows the entries behind it — and the app then renders
+/// raw keys like "tab.overview". These tests fail instead.
+struct LocalizationIntegrityTests {
+
+    private static let locales = ["Base", "de", "es", "fr", "nl"]
+
+    /// Keys rendered without a `defaultValue:`, so a missing entry is visible to users.
+    private static let keysWithoutFallback = [
+        "tab.overview",
+        "tab.components",
+        "tab.batteries",
+        "tab.chargers",
+    ]
+
+    private func table(for locale: String) throws -> [String: String] {
+        let bundle = Bundle.main
+        guard let url = bundle.url(
+            forResource: "Localizable",
+            withExtension: "strings",
+            subdirectory: nil,
+            localization: locale
+        ) else {
+            throw LocalizationTestError.tableMissing(locale)
+        }
+        let data = try Data(contentsOf: url)
+        let parsed = try PropertyListSerialization.propertyList(from: data, format: nil)
+        guard let table = parsed as? [String: String] else {
+            throw LocalizationTestError.tableMalformed(locale)
+        }
+        return table
+    }
+
+    @Test func everyLocaleProvidesTheKeysThatHaveNoFallback() async throws {
+        for locale in Self.locales {
+            let table = try table(for: locale)
+            for key in Self.keysWithoutFallback {
+                #expect(table[key] != nil, "\(locale): missing \(key), the UI would show the raw key")
+                #expect(
+                    table[key] != key,
+                    "\(locale): \(key) is not translated"
+                )
+            }
+        }
+    }
+
+    @Test func noValueSpansMultipleLines() async throws {
+        for locale in Self.locales {
+            let table = try table(for: locale)
+            for (key, value) in table {
+                #expect(
+                    !value.contains("\n"),
+                    "\(locale): \(key) contains a real newline; removing such an entry line by line corrupts the table"
+                )
+            }
+        }
+    }
+
+    @Test func retiredProKeysAreGone() async throws {
+        for locale in Self.locales {
+            let table = try table(for: locale)
+            let leftovers = table.keys.filter { $0.hasPrefix("cable.pro.") }
+            #expect(leftovers.isEmpty, "\(locale): dead PRO keys \(leftovers.sorted())")
+        }
+    }
+}
+
+private enum LocalizationTestError: Error {
+    case tableMissing(String)
+    case tableMalformed(String)
+}
diff --git a/CableUITestsScreenshot/LocalizedTabBarUITests.swift b/CableUITestsScreenshot/LocalizedTabBarUITests.swift
new file mode 100644
index 0000000..ab90356
--- /dev/null
+++ b/CableUITestsScreenshot/LocalizedTabBarUITests.swift
@@ -0,0 +1,62 @@
+import XCTest
+
+/// Reproduces the regression where the tab bar rendered raw keys ("tab.overview") because a
+/// malformed entry in Localizable.strings hid every key behind it. The tab titles are looked up
+/// without a `defaultValue:`, so a broken table is immediately visible here.
+final class LocalizedTabBarUITests: XCTestCase {
+
+    override func setUpWithError() throws {
+        try super.setUpWithError()
+        continueAfterFailure = false
+        XCUIDevice.shared.orientation = .portrait
+    }
+
+    @MainActor
+    func testTabBarIsLocalizedInGerman() throws {
+        let app = XCUIApplication()
+        app.launchArguments = [
+            "--uitest-reset-data",
+            "--uitest-sample-data",
+            "-AppleLanguages", "(de)",
+            "-AppleLocale", "de_DE",
+        ]
+        app.launch()
+
+        openFirstSystem(in: app)
+
+        let expected = ["Übersicht", "Verbraucher", "Batterien", "Ladegeräte"]
+        for title in expected {
+            XCTAssertTrue(
+                app.buttons[title].waitForExistence(timeout: 15),
+                "Tab \"\(title)\" is missing — the German string table is not being read"
+            )
+        }
+
+        for rawKey in ["tab.overview", "tab.components", "tab.batteries", "tab.chargers"] {
+            XCTAssertFalse(
+                app.buttons[rawKey].exists,
+                "Tab bar shows the raw key \(rawKey) instead of a translation"
+            )
+        }
+    }
+
+    private func openFirstSystem(in app: XCUIApplication) {
+        let list: XCUIElement
+        if app.collectionViews["systems-list"].waitForExistence(timeout: 15) {
+            list = app.collectionViews["systems-list"]
+        } else {
+            list = app.collectionViews.firstMatch
+        }
+        XCTAssertTrue(list.waitForExistence(timeout: 15))
+
+        let firstCell = list.cells.element(boundBy: 0)
+        XCTAssertTrue(firstCell.waitForExistence(timeout: 10))
+
+        let cellButton = firstCell.buttons.firstMatch
+        if cellButton.exists {
+            cellButton.tap()
+        } else {
+            firstCell.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5)).tap()
+        }
+    }
+}