diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 24640450c7..cded82ac7a 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -408,7 +408,6 @@ static void rv64_thead_c906_cpu_init(Object *obj)
 
     cpu->cfg.ext_g = true;
     cpu->cfg.ext_u = true;
-    cpu->cfg.ext_s = true;
     cpu->cfg.ext_icsr = true;
     cpu->cfg.ext_zfh = true;
     cpu->cfg.mmu = true;
@@ -843,7 +842,7 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    if (cpu->cfg.ext_s && !cpu->cfg.ext_u) {
+    if (riscv_has_ext(env, RVS) && !cpu->cfg.ext_u) {
         error_setg(errp,
                    "Setting S extension without U extension is illegal");
         return;
@@ -855,7 +854,7 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    if (cpu->cfg.ext_h && !cpu->cfg.ext_s) {
+    if (cpu->cfg.ext_h && !riscv_has_ext(env, RVS)) {
         error_setg(errp, "H extension implicitly requires S-mode");
         return;
     }
@@ -1168,7 +1167,7 @@ static void riscv_cpu_sync_misa_cfg(CPURISCVState *env)
     if (riscv_has_ext(env, RVC)) {
         ext |= RVC;
     }
-    if (riscv_cpu_cfg(env)->ext_s) {
+    if (riscv_has_ext(env, RVS)) {
         ext |= RVS;
     }
     if (riscv_cpu_cfg(env)->ext_u) {
@@ -1507,6 +1506,8 @@ static const RISCVCPUMisaExtConfig misa_ext_cfgs[] = {
      .misa_bit = RVE, .enabled = false},
     {.name = "m", .description = "Integer multiplication and division",
      .misa_bit = RVM, .enabled = true},
+    {.name = "s", .description = "Supervisor-level instructions",
+     .misa_bit = RVS, .enabled = true},
 };
 
 static void riscv_cpu_add_misa_properties(Object *cpu_obj)
@@ -1530,7 +1531,6 @@ static void riscv_cpu_add_misa_properties(Object *cpu_obj)
 static Property riscv_cpu_extensions[] = {
     /* Defaults for standard extensions */
     DEFINE_PROP_BOOL("g", RISCVCPU, cfg.ext_g, false),
-    DEFINE_PROP_BOOL("s", RISCVCPU, cfg.ext_s, true),
     DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
     DEFINE_PROP_BOOL("v", RISCVCPU, cfg.ext_v, false),
     DEFINE_PROP_BOOL("h", RISCVCPU, cfg.ext_h, true),
@@ -1647,7 +1647,6 @@ static void register_cpu_props(Object *obj)
      */
     if (cpu->env.misa_ext != 0) {
         cpu->cfg.ext_v = misa_ext & RVV;
-        cpu->cfg.ext_s = misa_ext & RVS;
         cpu->cfg.ext_u = misa_ext & RVU;
         cpu->cfg.ext_h = misa_ext & RVH;
         cpu->cfg.ext_j = misa_ext & RVJ;
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 71540a33ec..8b8e541e5f 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -423,7 +423,6 @@ typedef struct {
 
 struct RISCVCPUConfig {
     bool ext_g;
-    bool ext_s;
     bool ext_u;
     bool ext_h;
     bool ext_j;