diff --git a/src/osmo_gsm_tester/templates/srsenb_sib.conf.tmpl b/src/osmo_gsm_tester/templates/srsenb_sib.conf.tmpl
index 201d022..70e642c 100644
--- a/src/osmo_gsm_tester/templates/srsenb_sib.conf.tmpl
+++ b/src/osmo_gsm_tester/templates/srsenb_sib.conf.tmpl
@@ -46,7 +46,11 @@
             {
                 high_speed_flag = false;
                 prach_config_index = 3;
+% if int(enb['num_prb']) <= 6:
+                prach_freq_offset = 0;
+% else:
                 prach_freq_offset = 2;
+% endif
                 zero_correlation_zone_config = 5;
             };
         };