diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index fba5ce7118..821006f42a 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -2166,24 +2166,24 @@ static void riscv_init_max_cpu_extensions(Object *obj)
     set_misa(env, env->misa_mxl, env->misa_ext | RVG | RVJ | RVV);
 
     for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
-        object_property_set_bool(obj, prop->name, true, NULL);
+        isa_ext_update_enabled(cpu, prop->offset, true);
     }
 
     /* set vector version */
     env->vext_ver = VEXT_VERSION_1_00_0;
 
     /* Zfinx is not compatible with F. Disable it */
-    object_property_set_bool(obj, "zfinx", false, NULL);
-    object_property_set_bool(obj, "zdinx", false, NULL);
-    object_property_set_bool(obj, "zhinx", false, NULL);
-    object_property_set_bool(obj, "zhinxmin", false, NULL);
+    isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zfinx), false);
+    isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zdinx), false);
+    isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zhinx), false);
+    isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zhinxmin), false);
 
-    object_property_set_bool(obj, "zce", false, NULL);
-    object_property_set_bool(obj, "zcmp", false, NULL);
-    object_property_set_bool(obj, "zcmt", false, NULL);
+    isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zce), false);
+    isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zcmp), false);
+    isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zcmt), false);
 
     if (env->misa_mxl != MXL_RV32) {
-        object_property_set_bool(obj, "zcf", false, NULL);
+        isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zcf), false);
     }
 }