diff --git a/drivers/tty/arch/earm/rs232.c b/drivers/tty/arch/earm/rs232.c
index 13d817591..f9a9e8777 100644
--- a/drivers/tty/arch/earm/rs232.c
+++ b/drivers/tty/arch/earm/rs232.c
@@ -266,8 +266,9 @@ rs_write(register tty_t *tp, int try)
 		tp->tty_outcum += count;
 		if ((tp->tty_outleft -= count) == 0) {
 			/* Output is finished, reply to the writer. */
-			chardriver_reply_task(tp->tty_outcaller, tp->tty_outid,
-				tp->tty_outcum);
+			if (tp->tty_outcaller != KERNEL)
+				chardriver_reply_task(tp->tty_outcaller,
+					tp->tty_outid, tp->tty_outcum);
 			tp->tty_outcum = 0;
 			tp->tty_outcaller = NONE;
 		}
@@ -275,7 +276,9 @@ rs_write(register tty_t *tp, int try)
 	}
 	if (tp->tty_outleft > 0 && tp->tty_termios.c_ospeed == B0) {
 		/* Oops, the line has hung up. */
-		chardriver_reply_task(tp->tty_outcaller, tp->tty_outid, EIO);
+		if (tp->tty_outcaller != KERNEL)
+			chardriver_reply_task(tp->tty_outcaller, tp->tty_outid,
+				EIO);
 		tp->tty_outleft = tp->tty_outcum = 0;
 		tp->tty_outcaller = NONE;
 	}
diff --git a/drivers/tty/arch/i386/console.c b/drivers/tty/arch/i386/console.c
index efb49e852..27d95db5b 100644
--- a/drivers/tty/arch/i386/console.c
+++ b/drivers/tty/arch/i386/console.c
@@ -223,10 +223,11 @@ int try;
 
   flush(cons);			/* transfer anything buffered to the screen */
 
-  /* Reply to the writer if all output is finished or if an error occured. */
+  /* Reply to the writer if all output is finished or if an error occurred. */
   if (tp->tty_outleft == 0 || result != OK) {
-	chardriver_reply_task(tp->tty_outcaller, tp->tty_outid,
-		result != OK ? result : tp->tty_outcum);
+	if (tp->tty_outcaller != KERNEL)
+		chardriver_reply_task(tp->tty_outcaller, tp->tty_outid,
+			result != OK ? result : tp->tty_outcum);
 	tp->tty_outcum = tp->tty_outleft = 0;
 	tp->tty_outcaller = NONE;
   }
diff --git a/drivers/tty/arch/i386/rs232.c b/drivers/tty/arch/i386/rs232.c
index d98979d3d..0e29628e3 100644
--- a/drivers/tty/arch/i386/rs232.c
+++ b/drivers/tty/arch/i386/rs232.c
@@ -274,15 +274,17 @@ static int rs_write(register tty_t *tp, int try)
 	tp->tty_outcum += count;
 	if ((tp->tty_outleft -= count) == 0) {
 		/* Output is finished, reply to the writer. */
-		chardriver_reply_task(tp->tty_outcaller, tp->tty_outid,
-			tp->tty_outcum);
+		if (tp->tty_outcaller != KERNEL)
+			chardriver_reply_task(tp->tty_outcaller, tp->tty_outid,
+				tp->tty_outcum);
 		tp->tty_outcum = 0;
 		tp->tty_outcaller = NONE;
 	}
   }
   if (tp->tty_outleft > 0 && tp->tty_termios.c_ospeed == B0) {
 	/* Oops, the line has hung up. */
-	chardriver_reply_task(tp->tty_outcaller, tp->tty_outid, EIO);
+	if (tp->tty_outcaller != KERNEL)
+		chardriver_reply_task(tp->tty_outcaller, tp->tty_outid, EIO);
 	tp->tty_outleft = tp->tty_outcum = 0;
 	tp->tty_outcaller = NONE;
   }