1 files changed, 3 insertions, 1 deletions

diff --git a/lib-src/make-docfile.c b/lib-src/make-docfile.c
index ba54202954b..1ec365f3446 100644
--- a/lib-src/make-docfile.c
+++ b/lib-src/make-docfile.c
@@ -1149,8 +1149,10 @@ scan_lisp_file (const char *filename, const char *mode)
             }
         }
 
+      /* defcustom can only occur in uncompiled Lisp files.  */
       else if (! strcmp (buffer, "defvar")
-               || ! strcmp (buffer, "defconst"))
+               || ! strcmp (buffer, "defconst")
+               || ! strcmp (buffer, "defcustom"))
         {
           char c1 = 0, c2 = 0;
           type = 'V';