diff --git a/CHANGES b/CHANGES
index 4e1f09e..2a12aba 100644
--- a/CHANGES
+++ b/CHANGES
@@ -23,6 +23,9 @@ corrections:
 	socat option -x did not print packet direction, timestamp etc; thanks
 	to Anthony Sharobaiko for sending a patch
 
+	address PTY does not take any parameters but did not report an error
+	when some were given
+
 ####################### V 1.7.1.3:
 
 security:
diff --git a/test.sh b/test.sh
index be422b3..68dc452 100755
--- a/test.sh
+++ b/test.sh
@@ -1,6 +1,6 @@
 #! /bin/bash
 # source: test.sh
-# Copyright Gerhard Rieger 2001-2010
+# Copyright Gerhard Rieger 2001-2011
 # Published under the GNU General Public License V.2, see file COPYING
 
 # perform lots of tests on socat
@@ -10409,6 +10409,36 @@ esac
 N=$((N+1))
 
 
+# PTY address allowed to sepcify address parameters but ignored them
+NAME=PTY_VOIDARG
+case "$TESTS" in
+*%functions%*|*%bugs%*|*%pty%*|*%$NAME%*)
+TEST="$NAME: check if address params of PTY produce error"
+# invoke socat with address PTY and some param; expect an error
+if ! eval $NUMCOND; then :; else
+tf="$td/test$N.stdout"
+te="$td/test$N.stderr"
+tdiff="$td/test$N.diff"
+da="test$N $(date) $RANDOM"
+CMD0="$SOCAT $opts /dev/null PTY:/tmp/xyz"
+printf "test $F_n $TEST... " $N
+$CMD0 >/dev/null 2>"${te}0"
+rc0=$?
+if [ $rc0 -ne 0 ]; then
+    $PRINTF "$OK\n"
+    numOK=$((numOK+1))
+else
+    $PRINTF "$FAILED\n"
+    echo "$CMD0"
+    cat "${te}0"
+    numFAIL=$((numFAIL+1))
+fi
+fi # NUMCOND
+ ;;
+esac
+N=$((N+1))
+
+
 ###############################################################################
 # here come tests that might affect your systems integrity. Put normal tests
 # before this paragraph.
diff --git a/xio-pty.c b/xio-pty.c
index c478d7c..dff08a5 100644
--- a/xio-pty.c
+++ b/xio-pty.c
@@ -1,5 +1,5 @@
 /* source: xio-pty.c */
-/* Copyright Gerhard Rieger 2002-2009 */
+/* Copyright Gerhard Rieger 2002-2011 */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 /* this file contains the source for creating pty addresses */
@@ -47,6 +47,10 @@ static int xioopen_pty(int argc, const char *argv[], struct opt *opts, int xiofl
 				   compatibility we choose "no" as default */
    struct timespec pollintv = { PTY_INTERVALL };
 
+   if (argc != 1) {
+      Error2("%s: wrong number of parameters (%d instead of 0)", argv[0], argc-1);
+   }
+
    xfd->stream.howtoend = END_CLOSE;
 
    if (applyopts_single(&xfd->stream, opts, PH_INIT) < 0)  return -1;