1 files changed, 1 insertions, 0 deletions

diff --git a/src/process.c b/src/process.c
index 454278a5a27..ebaaf33e57f 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1157,6 +1157,7 @@ If PROCESS has not yet exited or died, return 0.  */)
 DEFUN ("process-id", Fprocess_id, Sprocess_id, 1, 1, 0,
        doc: /* Return the process id of PROCESS.
 This is the pid of the external process which PROCESS uses or talks to.
+It is a fixnum if the value is small enough, otherwise a bignum.
 For a network, serial, and pipe connections, this value is nil.  */)
   (register Lisp_Object process)
 {