diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c
index 197ff2fd5d..666ae0ff8c 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c
@@ -1072,15 +1072,15 @@ void nr_add_msg3(module_id_t module_idP, int CC_id, frame_t frameP, sub_frame_t
     return;
   }
 
-  uint16_t *vrb_map_UL =
-      &RC.nrmac[module_idP]->common_channels[CC_id].vrb_map_UL[ra->Msg3_slot * MAX_BWP_SIZE];
+  const uint16_t mask = SL_to_bitmap(ra->msg3_startsymb, ra->msg3_nrsymb);
+  uint16_t *vrb_map_UL = &RC.nrmac[module_idP]->common_channels[CC_id].vrb_map_UL[ra->Msg3_slot * MAX_BWP_SIZE];
   for (int i = 0; i < ra->msg3_nb_rb; ++i) {
-    AssertFatal(!vrb_map_UL[i + ra->msg3_first_rb + ra->msg3_bwp_start],
+    AssertFatal(!(vrb_map_UL[i + ra->msg3_first_rb + ra->msg3_bwp_start] & mask),
                 "RB %d in %4d.%2d is already taken, cannot allocate Msg3!\n",
                 i + ra->msg3_first_rb,
                 ra->Msg3_frame,
                 ra->Msg3_slot);
-    vrb_map_UL[i + ra->msg3_first_rb + ra->msg3_bwp_start] |= SL_to_bitmap(ra->msg3_startsymb, ra->msg3_nrsymb);
+    vrb_map_UL[i + ra->msg3_first_rb + ra->msg3_bwp_start] |= mask;
   }
 
   LOG_D(NR_MAC, "[gNB %d][RAPROC] Frame %d, Slot %d : CC_id %d RA is active, Msg3 in (%d,%d)\n", module_idP, frameP, slotP, CC_id, ra->Msg3_frame, ra->Msg3_slot);