diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index a33dc30be8..1cfc6a53a0 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -65,6 +65,7 @@
 #define RVS RV('S')
 #define RVU RV('U')
 #define RVH RV('H')
+#define RVJ RV('J')
 
 /* S extension denotes that Supervisor mode exists, however it is possible
    to have a core that support S mode but does not have an MMU and there
@@ -291,6 +292,7 @@ struct RISCVCPU {
         bool ext_s;
         bool ext_u;
         bool ext_h;
+        bool ext_j;
         bool ext_v;
         bool ext_zba;
         bool ext_zbb;