diff --git a/riscv/insns/wrs_nto.h b/riscv/insns/wrs_nto.h
index 710e6701..7a4fe671 100644
--- a/riscv/insns/wrs_nto.h
+++ b/riscv/insns/wrs_nto.h
@@ -1,3 +1,5 @@
+require_extension(EXT_ZAWRS);
+
 if (get_field(STATE.mstatus->read(), MSTATUS_TW)) {
   require_privilege(PRV_M);
 } else if (STATE.v) {
diff --git a/riscv/insns/wrs_sto.h b/riscv/insns/wrs_sto.h
index 4e71aa07..24d37a7f 100644
--- a/riscv/insns/wrs_sto.h
+++ b/riscv/insns/wrs_sto.h
@@ -1 +1,3 @@
+require_extension(EXT_ZAWRS);
+
 // WRS.STO stalls for a short duration