diff --git a/girepository/gitypes.h b/girepository/gitypes.h
index d15b121..9df35d5 100644
--- a/girepository/gitypes.h
+++ b/girepository/gitypes.h
@@ -164,7 +164,12 @@ typedef GIBaseInfo GIErrorDomainInfo;
  */
 typedef struct _GIUnresolvedInfo GIUnresolvedInfo;
 
-union _GIArgument
+/**
+ * GIArgument:
+ *
+ * Stores a argument of varying type
+ */
+typedef union 
 {
   gboolean v_boolean;
   gint8    v_int8;
@@ -187,8 +192,9 @@ union _GIArgument
   gsize    v_size;
   gchar *  v_string;
   gpointer v_pointer;
-};
-typedef union _GIArgument GIArgument;
+} GIArgument;
+
+
 
 /**
  * GIInfoType:
