1 files changed, 4 insertions, 1 deletions

diff --git a/src/lread.c b/src/lread.c
index 5e3ae083c46..1f24ecbf868 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -3325,7 +3325,10 @@ or variables, and cons cells `(provide . FEATURE)' and `(require . FEATURE)'.");
   Vload_file_name = Qnil;
 
   DEFVAR_LISP ("user-init-file", &Vuser_init_file,
-    "File name, including directory, of user's initialization file.");
+    "File name, including directory, of user's initialization file.
+If the file loaded had extension `.elc' and there was a corresponding `.el'
+file, this variable contains the name of the .el file, suitable for use
+by functions like `custom-save-all' which edit the init file.");
   Vuser_init_file = Qnil;
 
   DEFVAR_LISP ("current-load-list", &Vcurrent_load_list,