Fix header tags
diff --git a/src/hb-open-type-private.hh b/src/hb-open-type-private.hh
index d2fbb21..59c7866 100644
--- a/src/hb-open-type-private.hh
+++ b/src/hb-open-type-private.hh
@@ -24,8 +24,8 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_OPEN_TYPES_PRIVATE_HH
-#define HB_OPEN_TYPES_PRIVATE_HH
+#ifndef HB_OPEN_TYPE_PRIVATE_HH
+#define HB_OPEN_TYPE_PRIVATE_HH
 
 #include "hb-private.h"