diff --git a/contrib/testpbx/configs/vars.xml b/contrib/testpbx/configs/vars.xml
index 1cb826d..5ef16c9 100644
--- a/contrib/testpbx/configs/vars.xml
+++ b/contrib/testpbx/configs/vars.xml
@@ -255,8 +255,8 @@
        127 - BV32
 
   -->
-  <X-PRE-PROCESS cmd="set" data="global_codec_prefs=OPUS,G722,PCMU,PCMA,VP8"/>
-  <X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=OPUS,G722,PCMU,PCMA,VP8"/>
+  <X-PRE-PROCESS cmd="set" data="global_codec_prefs=OPUS,G722,PCMU,PCMA,VP8,GSM,AMR"/>
+  <X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=OPUS,G722,PCMU,PCMA,VP8,GSM,AMR"/>
 
   <!--
       xmpp_client_profile and xmpp_server_profile