1 files changed, 5 insertions, 5 deletions

diff --git a/src/lisp.h b/src/lisp.h
index 2d25f781091..80e01492c37 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3480,15 +3480,15 @@ struct Lisp_Fwd
   enum Lisp_Fwd_Type type : 8;
   union
   {
-    intmax_t *intvar;
-    bool *boolvar;
-    Lisp_Object *objvar;
+    intmax_t *intvar;           /* when type == Lisp_Fwd_Int */
+    bool *boolvar;              /* when type == Lisp_Fwd_Bool */
+    Lisp_Object *objvar;        /* when type == Lisp_Fwd_Obj */
     struct
     {
       uint16_t offset;
       enum Lisp_Fwd_Predicate predicate : 8;
-    } buf;
-    int kbdoffset;
+    } buf;                      /* when type == Lisp_Fwd_Buffer_Obj */
+    int kbdoffset;              /* when type == Lisp_Fwd_Kboard_Obj */
   } u;
 };