diff --git a/PKHeX.Core/Legality/Verifiers/Misc/Gen4GlobalTradeRules.cs b/PKHeX.Core/Legality/Verifiers/Misc/Gen4GlobalTradeRules.cs
index 54ea94200..52d853b86 100644
--- a/PKHeX.Core/Legality/Verifiers/Misc/Gen4GlobalTradeRules.cs
+++ b/PKHeX.Core/Legality/Verifiers/Misc/Gen4GlobalTradeRules.cs
@@ -12,8 +12,10 @@ public static bool IsRequiredGTS(ITrainerInfo tr, LanguageID currentLanguage)
         if (tr.Generation != 4)
             return false; // only applies to Gen4
 
-        // Cannot trade only if the trainer is Korean and the game language is not Korean.
-        return (LanguageID)tr.Language == LanguageID.Korean && currentLanguage != LanguageID.Korean;
+        // Korean and International can only exchange Pokémon via GTS.
+        var isKoreanTrainer = (LanguageID)tr.Language == LanguageID.Korean;
+        var isKoreanEntity = currentLanguage == LanguageID.Korean;
+        return isKoreanTrainer != isKoreanEntity;
     }
 
     /// <inheritdoc cref="IsRomanizedKoreanTrainerName(ReadOnlySpan{char})"/>