diff --git a/src/keyboard.c b/src/keyboard.c
index de91b40d295..9c41fa91351 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -6685,10 +6685,10 @@ tty_read_avail_input (struct display *display,
                       struct input_event *buf,
                       int numchars, int expected)
 {
-  /* Using numchars - 1 here avoids reading more than the buf can
+  /* Using numchars here avoids reading more than the buf can
      really hold.  That may prevent loss of characters on some systems
      when input is stuffed at us.  */
-  unsigned char cbuf[numchars - 1];
+  unsigned char cbuf[numchars];
   int n_to_read, i;
   struct tty_display_info *tty = display->display_info.tty;
   int nread = 0;