diff --git a/Sources/CodexBar/Localization.swift b/Sources/CodexBar/Localization.swift
index 38a6918e8b..d9fc9a3352 100644
--- a/Sources/CodexBar/Localization.swift
+++ b/Sources/CodexBar/Localization.swift
@@ -214,7 +214,22 @@ func L(_ key: String, language: String) -> String {
 }
 
 func codexBarLocalizedLocale() -> Locale {
-    let language = resolvedAppLanguage()
+    codexBarLocale(forLanguage: resolvedAppLanguage())
+}
+
+/// Returns the locale of the resource bundle currently selected by `L`.
+///
+/// This can differ from `Locale.current` when the app falls back to a supported language. Plural
+/// formatting must use this locale so it follows the same language as the resolved strings.
+func codexBarLocalizedResourceLocale() -> Locale {
+    let bundleURL = localizedBundle().bundleURL
+    guard bundleURL.pathExtension == "lproj" else {
+        return codexBarLocalizedLocale()
+    }
+    return codexBarLocale(forLanguage: bundleURL.deletingPathExtension().lastPathComponent)
+}
+
+private func codexBarLocale(forLanguage language: String) -> Locale {
     guard !language.isEmpty else { return .current }
     let normalized = language.lowercased()
     if normalized == "ar" || normalized.hasPrefix("ar-") {
diff --git a/Sources/CodexBar/UsagePaceText.swift b/Sources/CodexBar/UsagePaceText.swift
index 32823b6d22..bbe65498ec 100644
--- a/Sources/CodexBar/UsagePaceText.swift
+++ b/Sources/CodexBar/UsagePaceText.swift
@@ -39,19 +39,21 @@ enum UsagePaceText {
 
     static func sessionEquivalentDetail(forecast: SessionEquivalentForecast) -> SessionEquivalentDetail {
         let displayedEstimate = Self.boundedFullWindowCount(forecast.estimatedWindowsToExhaustWeekly)
-        let numberText = String.localizedStringWithFormat(
-            L("≈%d full 5h windows of weekly left · %d windows until reset"),
-            displayedEstimate,
-            forecast.windowsUntilReset)
+        let formattingLocale = codexBarLocalizedResourceLocale()
+        let numberText = String(
+            format: L("≈%d full 5h windows of weekly left · %d windows until reset"),
+            locale: formattingLocale,
+            arguments: [displayedEstimate, forecast.windowsUntilReset])
         let verdictText: String
         if forecast.estimatedWindowsToExhaustWeekly >= forecast.availableWindowsUntilReset {
             verdictText = L("Weekly cannot run out before reset at this pace")
         } else {
             let windowsEarly = Self.boundedWindowCount(
                 forecast.availableWindowsUntilReset - forecast.estimatedWindowsToExhaustWeekly)
-            verdictText = String.localizedStringWithFormat(
-                L("Weekly can run out ≈%d windows early"),
-                max(1, windowsEarly))
+            verdictText = String(
+                format: L("Weekly can run out ≈%d windows early"),
+                locale: formattingLocale,
+                arguments: [max(1, windowsEarly)])
         }
         return SessionEquivalentDetail(
             verdictText: verdictText,
diff --git a/Tests/CodexBarTests/LocalizationBundleCacheTests.swift b/Tests/CodexBarTests/LocalizationBundleCacheTests.swift
index 7a7d2572c2..3ab0ae15df 100644
--- a/Tests/CodexBarTests/LocalizationBundleCacheTests.swift
+++ b/Tests/CodexBarTests/LocalizationBundleCacheTests.swift
@@ -54,6 +54,19 @@ struct LocalizationBundleCacheTests {
         #expect(bundle.bundleURL.lastPathComponent == "en.lproj")
     }
 
+    @Test
+    func `format locale follows the resolved resource bundle`() {
+        let english = CodexBarLocalizationOverride.$appLanguage.withValue("en") {
+            codexBarLocalizedResourceLocale()
+        }
+        #expect(english.language.languageCode?.identifier == "en")
+
+        let fallback = CodexBarLocalizationOverride.$appLanguage.withValue("zz-unknown") {
+            codexBarLocalizedResourceLocale()
+        }
+        #expect(fallback.language.languageCode?.identifier == "en")
+    }
+
     @Test
     func `resolution survives an explicit cache reset`() {
         let first = CodexBarLocalizationOverride.$appLanguage.withValue("uk") {