diff --git a/src/language.h b/src/language.h
--- a/src/language.h
+++ b/src/language.h
@@ -105,7 +105,7 @@ extern LanguageList _languages;
 extern const LanguageMetadata *_current_language;
 
 #ifdef WITH_ICU_SORT
-extern Collator *_current_collator;
+extern icu::Collator *_current_collator;
 #endif /* WITH_ICU_SORT */
 
 bool ReadLanguagePack(const LanguageMetadata *lang);