diff --git a/src/gfx_func.h b/src/gfx_func.h
--- a/src/gfx_func.h
+++ b/src/gfx_func.h
@@ -124,6 +124,7 @@ Dimension GetStringBoundingBox(const cha
 Dimension GetStringBoundingBox(StringID strid);
 uint32 FormatStringLinebreaks(char *str, const char *last, int maxw, FontSize start_fontsize = FS_NORMAL);
 int GetStringHeight(StringID str, int maxw);
+int GetStringLineCount(StringID str, int maxw);
 Dimension GetStringMultiLineBoundingBox(StringID str, const Dimension &suggestion);
 Dimension GetStringMultiLineBoundingBox(const char *str, const Dimension &suggestion);
 void LoadStringWidthTable(bool monospace = false);