diff --git a/scenarios/invite_prack/0003_test.yml.tt2 b/scenarios/invite_prack/0003_test.yml.tt2
index ecbabbd9..b04b6a70 100644
--- a/scenarios/invite_prack/0003_test.yml.tt2
+++ b/scenarios/invite_prack/0003_test.yml.tt2
@@ -162,7 +162,7 @@ sip_out:
       'CSeq: \d+ INVITE',
     ]
   - [
-      'INVITE sip:[% scenarios.0.responders.0.username %]@127.0.2.1:\d+;transport=udp SIP/2.0',
+      'INVITE sip:[% scenarios.0.responders.0.username %]@[% scenarios.0.responders.0.ip %]:[% scenarios.0.responders.0.port %];transport=udp SIP/2.0',
       'From: <sip:[% invite_prack_scenarios_test.testuser1012.phone_number %]@invite-prack.scenarios.test>;tag=[\w-]+',
       'To: <sip:[% scenarios.0.responders.0.username %]@invite-prack.scenarios.test>',
       'Supported: 100rel',
diff --git a/scenarios/invite_prack/0011_test.yml.tt2 b/scenarios/invite_prack/0011_test.yml.tt2
index 46876dec..94769692 100644
--- a/scenarios/invite_prack/0011_test.yml.tt2
+++ b/scenarios/invite_prack/0011_test.yml.tt2
@@ -15,12 +15,12 @@ flow:
 sip_in:
   - 'SIP/2.0 200 OK'
   - 'From: <sip:[% invite_prack_scenarios_test.testuser1012.phone_number %]@invite-prack.scenarios.test>;tag=[\w-]+'
-  - 'To: <sip:[% scenarios.0.responders.0.username %]@127.0.2.1>;tag=[\w-]+'
+  - 'To: <sip:[% scenarios.0.responders.0.username %]@[% scenarios.0.responders.0.ip %]>;tag=[\w-]+'
   - 'CSeq: \d+ PRACK'
 sip_out:
   - [
       'SIP/2.0 200 OK',
       'From: <sip:[% invite_prack_scenarios_test.testuser1012.phone_number %]@invite-prack.scenarios.test>;tag=[\w-]+',
-      'To: <sip:[% scenarios.0.responders.0.username %]@127.0.2.1>;tag=[\w-]+',
+      'To: <sip:[% scenarios.0.responders.0.username %]@[% scenarios.0.responders.0.ip %]>;tag=[\w-]+',
       'CSeq: \d+ PRACK',
     ]
diff --git a/scenarios/invite_prack/sipp_scenario00.xml b/scenarios/invite_prack/sipp_scenario00.xml
index e8ad881b..1b932829 100644
--- a/scenarios/invite_prack/sipp_scenario00.xml
+++ b/scenarios/invite_prack/sipp_scenario00.xml
@@ -11,7 +11,7 @@
       To: <sip:[field0 file="callee.csv" line=0]@[field3 file="callee.csv" line=0]>
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 1 INVITE
-      Contact: sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Type: application/sdp
       Content-Length: [len]
@@ -40,7 +40,7 @@
       To: <sip:[field0 file="callee.csv" line=0]@[field3 file="callee.csv" line=0]>[peer_tag_param]
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 1 ACK
-      Contact: sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Length: 0
 
@@ -57,7 +57,7 @@
       Supported: 100rel
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 2 INVITE
-      Contact: sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]>
       Max-Forwards: 70
       [field1 file="caller.csv" line=0]
       Content-Type: application/sdp
@@ -113,7 +113,7 @@
       [last_Call-ID:]
       [routes]
       CSeq: 2 ACK
-      Contact: sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Length: 0
 
@@ -129,7 +129,7 @@
       To: <sip:[field0 file="callee.csv" line=0]@[field3 file="callee.csv" line=0]>[peer_tag_param]
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 4 BYE
-      Contact: sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]>
       [routes]
       Max-Forwards: 70
       Content-Length: 0