diff --git a/src/modems/hayes.c b/src/modems/hayes.c
index a0c29a1..a84ecf5 100644
--- a/src/modems/hayes.c
+++ b/src/modems/hayes.c
@@ -843,7 +843,8 @@ static char * _hayes_message_to_pdu(HayesChannel * channel, char const * number,
 		+ strlen((data != NULL) ? data : "");
 	if(addr != NULL && (ret = malloc(len)) != NULL)
 	{
-		if(hayeschannel_has_quirks(channel,
+		/* XXX no longer require the channel here */
+		if(channel != NULL && hayeschannel_has_quirks(channel,
 					HAYES_QUIRK_WANT_SMSC_IN_PDU))
 			smsc = "00";
 		if(snprintf(ret, len, "%s%s%02lX%s%s%s%s%02lX%s", smsc, prefix,
diff --git a/tests/pdu.c b/tests/pdu.c
index c144ae7..c047044 100644
--- a/tests/pdu.c
+++ b/tests/pdu.c
@@ -37,18 +37,23 @@ static int _pdu(void);
 static int _pdu_decode(char const * pdu, char const * number,
 		char const * datetime, ModemMessageEncoding encoding,
 		char const * message);
+static int _pdu_encode(void);
 
 
 /* functions */
 /* pdu */
 static int _pdu(void)
 {
-	return _pdu_decode("07916407058099F9040B916407752743"
-			"F60000990121017580001554747A0E4A"
-			"CF416110945805B5CBF379F85C06",
-			"+46705772346", "12/10/1999 12:57:08",
-			MODEM_MESSAGE_ENCODING_UTF8,
-			"This is a PDU message");
+	int ret = 0;
+
+	ret |= (_pdu_decode("07916407058099F9040B916407752743"
+				"F60000990121017580001554747A0E4A"
+				"CF416110945805B5CBF379F85C06",
+				"+46705772346", "12/10/1999 12:57:08",
+				MODEM_MESSAGE_ENCODING_UTF8,
+				"This is a PDU message") != 0) ? 1 : 0;
+	ret |= (_pdu_encode() != 0) ? 2 : 0;
+	return ret;
 }
 
 
@@ -111,8 +116,26 @@ static int _pdu_decode(char const * pdu, char const * number,
 }
 
 
+/* pdu_encode */
+static int _pdu_encode(void)
+{
+	int ret;
+	char * pdu;
+	char const number[] = "1234";
+	ModemMessageEncoding encoding = MODEM_MESSAGE_ENCODING_ASCII;
+	char const string[] = "This is just a test.";
+
+	if((pdu = _hayes_message_to_pdu(NULL, number, encoding,
+					sizeof(string) - 1, string)) == NULL)
+		return -1;
+	ret = _pdu_decode(pdu, number, NULL, encoding, string);
+	free(pdu);
+	return ret;
+}
+
+
 /* main */
 int main(void)
 {
-	return (_pdu() == 0) ? 0 : 2;
+	return (_pdu() << 1);
 }
diff --git a/tests/tests.sh b/tests/tests.sh
index 1c5cf12..834ad32 100755
--- a/tests/tests.sh
+++ b/tests/tests.sh
@@ -101,10 +101,10 @@ FAILED=
 echo "Performing tests:" 1>&2
 _test "hayes"
 _test "modems"
-_test "pdu"
 _test "plugins"
 _test "ussd"
 echo "Expected failures:" 1>&2
+_fail "pdu"
 if [ -n "$FAILED" ]; then
 	echo "Failed tests:$FAILED" 1>&2
 	exit 2