diff --git a/src/newgrf_text.h b/src/newgrf_text.h
--- a/src/newgrf_text.h
+++ b/src/newgrf_text.h
@@ -49,7 +49,7 @@ void RewindTextRefStack();
 bool UsingNewGRFTextStack();
 struct TextRefStack *CreateTextRefStackBackup();
 void RestoreTextRefStackBackup(struct TextRefStack *backup);
-uint RemapNewGRFStringControlCode(uint scc, char *buf_start, char **buff, const char **str, int64 *argv, uint argv_size, bool modify_argv);
+uint RemapNewGRFStringControlCode(uint scc, const char **str, int64 *argv, uint argv_size, bool modify_argv);
 
 /** Mapping of language data between a NewGRF and OpenTTD. */
 struct LanguageMap {