diff --git a/srsenb/src/stack/mac/scheduler_ue.cc b/srsenb/src/stack/mac/scheduler_ue.cc
index 96e6cd6eb..8d6950fa1 100644
--- a/srsenb/src/stack/mac/scheduler_ue.cc
+++ b/srsenb/src/stack/mac/scheduler_ue.cc
@@ -568,6 +568,7 @@ std::pair<int, int> sched_ue::compute_mcs_and_tbs(uint32_t               ue_cc_i
     tbs_bytes = carriers[ue_cc_idx].alloc_tbs_dl(nof_alloc_prbs, nof_re, req_bytes.second, &mcs);
   } else {
     // Fixed MCS
+    mcs       = carriers[ue_cc_idx].fixed_mcs_dl;
     tbs_bytes = sched_utils::get_tbs_bytes(
         (uint32_t)carriers[ue_cc_idx].fixed_mcs_dl, nof_alloc_prbs, cfg.use_tbs_index_alt, false);
   }
diff --git a/srsenb/test/mac/scheduler_test_common.cc b/srsenb/test/mac/scheduler_test_common.cc
index fdfe0175f..d3c98139c 100644
--- a/srsenb/test/mac/scheduler_test_common.cc
+++ b/srsenb/test/mac/scheduler_test_common.cc
@@ -875,6 +875,7 @@ int common_sched_tester::sim_cfg(sim_sched_args args)
   sim_args0 = std::move(args);
 
   sched::cell_cfg(sim_args0.cell_cfg); // call parent cfg
+  sched::set_sched_cfg(&sim_args0.sched_args);
 
   ue_tester.reset(new user_state_sched_tester{sim_args0.cell_cfg});
   output_tester.clear();
diff --git a/srsenb/test/mac/scheduler_test_rand.cc b/srsenb/test/mac/scheduler_test_rand.cc
index f5dea2d04..c07a685ae 100644
--- a/srsenb/test/mac/scheduler_test_rand.cc
+++ b/srsenb/test/mac/scheduler_test_rand.cc
@@ -426,13 +426,14 @@ void test_scheduler_rand(sched_sim_events sim)
 
 sched_sim_events rand_sim_params(uint32_t nof_ttis)
 {
-  sched_sim_events                        sim_gen;
-  uint32_t                                max_conn_dur = 10000, min_conn_dur = 500;
-  float                                   P_ul_sr = srsenb::randf() * 0.5, P_dl = srsenb::randf() * 0.5;
-  float                                   P_prach        = 0.99f;  // 0.1f + randf()*0.3f;
-  float                                   ul_sr_exps[]   = {1, 4}; // log rand
-  float                                   dl_data_exps[] = {1, 4}; // log rand
-  uint32_t                                max_nof_users  = 5;
+  auto             boolean_dist = []() { return std::uniform_int_distribution<>{0, 1}(srsenb::get_rand_gen()); };
+  sched_sim_events sim_gen;
+  uint32_t         max_conn_dur = 10000, min_conn_dur = 500;
+  float            P_ul_sr = srsenb::randf() * 0.5, P_dl = srsenb::randf() * 0.5;
+  float            P_prach        = 0.99f;  // 0.1f + randf()*0.3f;
+  float            ul_sr_exps[]   = {1, 4}; // log rand
+  float            dl_data_exps[] = {1, 4}; // log rand
+  uint32_t         max_nof_users  = 5;
   std::uniform_int_distribution<>         connection_dur_dist(min_conn_dur, max_conn_dur);
   std::uniform_int_distribution<uint32_t> dist_prb_idx(0, 5);
   uint32_t                                prb_idx = dist_prb_idx(srsenb::get_rand_gen());
@@ -444,6 +445,10 @@ sched_sim_events rand_sim_params(uint32_t nof_ttis)
   sim_gen.sim_args.default_ue_sim_cfg.periodic_cqi = true;
   sim_gen.sim_args.start_tti                       = 0;
   sim_gen.sim_args.sim_log                         = log_global.get();
+  sim_gen.sim_args.sched_args.pdsch_mcs =
+      boolean_dist() ? -1 : std::uniform_int_distribution<>{0, 24}(srsenb::get_rand_gen());
+  sim_gen.sim_args.sched_args.pusch_mcs =
+      boolean_dist() ? -1 : std::uniform_int_distribution<>{0, 24}(srsenb::get_rand_gen());
 
   generator.tti_events.resize(nof_ttis);
 
diff --git a/srsenb/test/mac/scheduler_test_utils.h b/srsenb/test/mac/scheduler_test_utils.h
index 0ecafa399..acb8fd7e1 100644
--- a/srsenb/test/mac/scheduler_test_utils.h
+++ b/srsenb/test/mac/scheduler_test_utils.h
@@ -109,6 +109,7 @@ struct sim_sched_args {
   std::vector<srsenb::sched_interface::cell_cfg_t> cell_cfg;
   srslte::log*                                     sim_log = nullptr;
   ue_ctxt_test_cfg                                 default_ue_sim_cfg{};
+  srsenb::sched_interface::sched_args_t            sched_args = {};
 };
 
 // generate all events up front