diff --git a/struct.c b/struct.c
index cd6d05a552..6303436122 100644
--- a/struct.c
+++ b/struct.c
@@ -1158,6 +1158,8 @@ rb_struct_dig(int argc, VALUE *argv, VALUE self)
 }
 
 /*
+ *  Document-class: Struct
+ *
  *  A Struct is a convenient way to bundle a number of attributes together,
  *  using accessor methods, without having to write an explicit class.
  *