1 files changed, 4 insertions, 2 deletions

diff --git a/src/cmds.c b/src/cmds.c
index d5cf5b0fedb..1e8ded46942 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -222,7 +222,8 @@ Whichever character you type to run this command is inserted.")
   else
     while (XINT (arg) > 0)
       {
-        XFASTINT (arg)--;       /* Ok since old and new vals both nonneg */
+        /* Ok since old and new vals both nonneg */
+        XSETFASTINT (arg, XFASTINT (arg) - 1);
         internal_self_insert (XINT (last_command_char), XFASTINT (arg) != 0);
       }
 
@@ -277,7 +278,8 @@ In Auto Fill mode, if no numeric arg, break the preceding line if it's long.")
         insert (&c1, 1);
       else
         internal_self_insert ('\n', !NILP (arg1));
-      XFASTINT (arg)--;         /* Ok since old and new vals both nonneg */
+      /* Ok since old and new vals both nonneg */
+      XSETFASTINT (arg, XFASTINT (arg) - 1);
     }
 
   if (flag)