Prefer C linkage
diff --git a/src/hb-font-private.h b/src/hb-font-private.h
index 7f54cbd..f91da83 100644
--- a/src/hb-font-private.h
+++ b/src/hb-font-private.h
@@ -33,6 +33,7 @@
 
 HB_BEGIN_DECLS
 
+
 /*
  * hb_font_funcs_t
  */