diff --git a/kernel/riscv.h b/kernel/riscv.h
index d80e78e..f7aaa8a 100644
--- a/kernel/riscv.h
+++ b/kernel/riscv.h
@@ -196,14 +196,16 @@ static inline uint64
 r_menvcfg()
 {
   uint64 x;
-  asm volatile("csrr %0, menvcfg" : "=r" (x) );
+  // asm volatile("csrr %0, menvcfg" : "=r" (x) );
+  asm volatile("csrr %0, 0x30a" : "=r" (x) );
   return x;
 }
 
 static inline void 
 w_menvcfg(uint64 x)
 {
-  asm volatile("csrw menvcfg, %0" : : "r" (x));
+  // asm volatile("csrw menvcfg, %0" : : "r" (x));
+  asm volatile("csrw 0x30a, %0" : : "r" (x));
 }
 
 // Physical Memory Protection