diff --git a/modules/rhizo_base/templates/osmo-bsc-head.erb b/modules/rhizo_base/templates/osmo-bsc-head.erb
index e8ecf2c..638ff2e 100644
--- a/modules/rhizo_base/templates/osmo-bsc-head.erb
+++ b/modules/rhizo_base/templates/osmo-bsc-head.erb
@@ -77,4 +77,7 @@ network
  handover2 penalty-time failed-ho 5
  handover2 penalty-time failed-assignment 5
  handover2 congestion-check 30
+<% if @mncc_codec != 'GSM' -%>
+ dyn_ts_allow_tch_f 0
+<% end -%>
  meas-feed destination 127.0.0.1 8888
diff --git a/modules/rhizo_base/templates/osmo-bsc-tail.erb b/modules/rhizo_base/templates/osmo-bsc-tail.erb
index 94c3230..1e2fb77 100644
--- a/modules/rhizo_base/templates/osmo-bsc-tail.erb
+++ b/modules/rhizo_base/templates/osmo-bsc-tail.erb
@@ -1,5 +1,9 @@
 msc 0
- codec-list fr1 fr3 hr3
+<% if @mncc_codec == 'GSM' -%>
+ codec-list fr1
+<% else -%>
+ codec-list hr3 fr3
+<% end -%>
  allow-emergency allow
  amr-config 12_2k forbidden
  amr-config 10_2k forbidden