diff --git a/Packages/ComposeUI/Sources/ComposeUI/Views/LanguagePicker.swift b/Packages/ComposeUI/Sources/ComposeUI/Views/LanguagePicker.swift
index 4680d5e9..22d6d9f1 100644
--- a/Packages/ComposeUI/Sources/ComposeUI/Views/LanguagePicker.swift
+++ b/Packages/ComposeUI/Sources/ComposeUI/Views/LanguagePicker.swift
@@ -30,7 +30,13 @@ struct LanguagePicker: View {
         if maybeIso639Code.last == "-" {
             maybeIso639Code = maybeIso639Code[..<maybeIso639Code.index(before: maybeIso639Code.endIndex)]
         }
-        let code = Locale.LanguageCode(String(maybeIso639Code))
+        let identifier = String(maybeIso639Code)
+        // mul (for multiple languages) and unk (unknown) are ISO codes, but not ones that akkoma permits, so we ignore them on all platforms
+        guard identifier != "mul",
+              identifier != "und" else {
+            return nil
+        }
+        let code = Locale.LanguageCode(identifier)
         if code.isISOLanguage {
             return code
         } else {
@@ -39,13 +45,10 @@ struct LanguagePicker: View {
     }
     
     private var codeFromPreferredLanguages: Locale.LanguageCode? {
-        if let identifier = Locale.preferredLanguages.first {
-            let code = Locale.LanguageCode(identifier)
-            if code.isISOLanguage {
-                return code
-            } else {
-                return nil
-            }
+        if let identifier = Locale.preferredLanguages.first,
+           case let code = Locale.LanguageCode(identifier),
+           code.isISOLanguage {
+            return code
         } else {
             return nil
         }
@@ -138,10 +141,12 @@ private struct LanguagePickerList: View {
             // make sure recents always contains the currently selected lang
             let recents = addRecentLang(languageCode)
             recentLangs = recents
+                .filter { $0 != "mul" && $0 != "und" }
                 .map { Lang(code: .init($0)) }
                 .sorted { $0.name < $1.name }
             
             langs = Locale.LanguageCode.isoLanguageCodes
+                .filter { $0.identifier != "mul" && $0.identifier != "und" }
                 .map { Lang(code: $0) }
                 .sorted { $0.name < $1.name }
         }