diff --git a/daemon/main.c b/daemon/main.c
index 898724fd9..1fe10c978 100644
--- a/daemon/main.c
+++ b/daemon/main.c
@@ -445,10 +445,10 @@ static void do_transcode_config(const char *name, charp_ht ht, struct transcode_
 			die("Failed to parse transform endpoint '%s' in transcode config '%s'", tfm, name);
 		char *iface = t_hash_table_lookup(ht, "local-interface");
 		if (iface)
-			tc->local_interface = STR(iface);
+			tc->local_interface = str_dup_str(STR_PTR(iface));
 		iface = t_hash_table_lookup(ht, "remote-interface");
 		if (iface)
-			tc->remote_interface = STR(iface);
+			tc->remote_interface = str_dup_str(STR_PTR(iface));
 		return;
 	}
 	else
diff --git a/t/auto-daemon-tests-transcode-config.pl b/t/auto-daemon-tests-transcode-config.pl
index 56499c88d..89a5b3d66 100755
--- a/t/auto-daemon-tests-transcode-config.pl
+++ b/t/auto-daemon-tests-transcode-config.pl
@@ -167,7 +167,7 @@ SDP
 rcv_no($sock_sig);
 
 $NGCP::Rtpengine::req_cb = sub {
-	($port_sig, $addr_sig, $cookie, $port_tc) = rcv($sock_sig, -1, qr/^(.{16}) d7:command9:transform5:mediald4:type5:audio5:codecld5:inputd5:codec4:PCMA12:payload typei8e10:clock ratei8000e8:channelsi1e6:format0:7:options0:e6:outputd5:codec4:PCMU12:payload typei0e10:clock ratei8000e8:channelsi1e6:format0:7:options0:eee11:destinationd6:family3:IP47:address11:203.0.113.14:porti(\d{5})eeee8:instance12:.{12}e$/);
+	($port_sig, $addr_sig, $cookie, $port_tc) = rcv($sock_sig, -1, qr/^(.{16}) d7:command9:transform5:mediald4:type5:audio5:codecld5:inputd5:codec4:PCMA12:payload typei8e10:clock ratei8000e8:channelsi1e6:format0:7:options0:e6:outputd5:codec4:PCMU12:payload typei0e10:clock ratei8000e8:channelsi1e6:format0:7:options0:eee11:destinationd6:family3:IP47:address11:203.0.113.14:porti(\d{5})eeee9:interface7:default8:instance12:.{12}e$/);
 	snd($sock_sig, $port_sig, $cookie . ' ' . Bencode::bencode( {
 				result => 'ok',
 				'call-id' => 'foobar',
@@ -249,7 +249,7 @@ $NGCP::Rtpengine::req_cb = undef;
 
 
 $NGCP::Rtpengine::req_cb = sub {
-	($port_sig, $addr_sig, $cookie, $port_tc) = rcv($sock_sig, -1, qr/^(.{16}) d7:command9:transform5:mediald4:type5:audio5:codecld5:inputd5:codec4:PCMA12:payload typei8e10:clock ratei8000e8:channelsi1e6:format0:7:options0:e6:outputd5:codec4:PCMU12:payload typei0e10:clock ratei8000e8:channelsi1e6:format0:7:options0:eee11:destinationd6:family3:IP47:address11:203.0.113.14:porti(\d{5})eeee8:instance12:.{12}e$/);
+	($port_sig, $addr_sig, $cookie, $port_tc) = rcv($sock_sig, -1, qr/^(.{16}) d7:command9:transform5:mediald4:type5:audio5:codecld5:inputd5:codec4:PCMA12:payload typei8e10:clock ratei8000e8:channelsi1e6:format0:7:options0:e6:outputd5:codec4:PCMU12:payload typei0e10:clock ratei8000e8:channelsi1e6:format0:7:options0:eee11:destinationd6:family3:IP47:address11:203.0.113.14:porti(\d{5})eeee9:interface7:default8:instance12:.{12}e$/);
 	snd($sock_sig, $port_sig, $cookie . ' ' . Bencode::bencode( {
 				result => 'ok',
 				'call-id' => 'foobar',
diff --git a/t/test4.conf b/t/test4.conf
index effeb527b..23710b312 100644
--- a/t/test4.conf
+++ b/t/test4.conf
@@ -27,8 +27,12 @@ address = 203.0.113.1
 source = PCMA
 destination = PCMU
 transform = 203.0.113.42:3334
+local-interface = default
+remote-interface = default
 
 [tc-PCMU-G722]
 source = PCMU
 destination = G722
 transform = 203.0.113.42:3334
+local-interface = default
+remote-interface = default