diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index e0f6e315a2..35a3563ff4 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -689,19 +689,11 @@ min        0000101 .......... 100 ..... 0110011 @r
 minu       0000101 .......... 101 ..... 0110011 @r
 max        0000101 .......... 110 ..... 0110011 @r
 maxu       0000101 .......... 111 ..... 0110011 @r
-bset       0010100 .......... 001 ..... 0110011 @r
-bclr       0100100 .......... 001 ..... 0110011 @r
-binv       0110100 .......... 001 ..... 0110011 @r
-bext       0100100 .......... 101 ..... 0110011 @r
 ror        0110000 .......... 101 ..... 0110011 @r
 rol        0110000 .......... 001 ..... 0110011 @r
 grev       0110100 .......... 101 ..... 0110011 @r
 gorc       0010100 .......... 101 ..... 0110011 @r
 
-bseti      00101. ........... 001 ..... 0010011 @sh
-bclri      01001. ........... 001 ..... 0010011 @sh
-binvi      01101. ........... 001 ..... 0010011 @sh
-bexti      01001. ........... 101 ..... 0010011 @sh
 rori       01100. ........... 101 ..... 0010011 @sh
 grevi      01101. ........... 101 ..... 0010011 @sh
 gorci      00101. ........... 101 ..... 0010011 @sh
@@ -722,3 +714,12 @@ roriw      0110000 .......... 101 ..... 0011011 @sh5
 greviw     0110100 .......... 101 ..... 0011011 @sh5
 gorciw     0010100 .......... 101 ..... 0011011 @sh5
 
+# *** RV32 Zbs Standard Extension ***
+bclr       0100100 .......... 001 ..... 0110011 @r
+bclri      01001. ........... 001 ..... 0010011 @sh
+bext       0100100 .......... 101 ..... 0110011 @r
+bexti      01001. ........... 101 ..... 0010011 @sh
+binv       0110100 .......... 001 ..... 0110011 @r
+binvi      01101. ........... 001 ..... 0010011 @sh
+bset       0010100 .......... 001 ..... 0110011 @r
+bseti      00101. ........... 001 ..... 0010011 @sh
diff --git a/target/riscv/insn_trans/trans_rvb.c.inc b/target/riscv/insn_trans/trans_rvb.c.inc
index a5bf40f95b..861364e3e5 100644
--- a/target/riscv/insn_trans/trans_rvb.c.inc
+++ b/target/riscv/insn_trans/trans_rvb.c.inc
@@ -1,5 +1,5 @@
 /*
- * RISC-V translation routines for the RVB draft and Zba Standard Extension.
+ * RISC-V translation routines for the RVB draft Zb[as] Standard Extension.
  *
  * Copyright (c) 2020 Kito Cheng, kito.cheng@sifive.com
  * Copyright (c) 2020 Frank Chang, frank.chang@sifive.com
@@ -24,11 +24,16 @@
     }                                            \
 } while (0)
 
+#define REQUIRE_ZBS(ctx) do {                    \
+    if (!RISCV_CPU(ctx->cs)->cfg.ext_zbs) {      \
+        return false;                            \
+    }                                            \
+} while (0)
+
 static void gen_clz(TCGv ret, TCGv arg1)
 {
     tcg_gen_clzi_tl(ret, arg1, TARGET_LONG_BITS);
 }
-
 static bool trans_clz(DisasContext *ctx, arg_clz *a)
 {
     REQUIRE_EXT(ctx, RVB);
@@ -165,13 +170,13 @@ static void gen_bset(TCGv ret, TCGv arg1, TCGv shamt)
 
 static bool trans_bset(DisasContext *ctx, arg_bset *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift(ctx, a, EXT_NONE, gen_bset);
 }
 
 static bool trans_bseti(DisasContext *ctx, arg_bseti *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift_imm_tl(ctx, a, EXT_NONE, gen_bset);
 }
 
@@ -187,13 +192,13 @@ static void gen_bclr(TCGv ret, TCGv arg1, TCGv shamt)
 
 static bool trans_bclr(DisasContext *ctx, arg_bclr *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift(ctx, a, EXT_NONE, gen_bclr);
 }
 
 static bool trans_bclri(DisasContext *ctx, arg_bclri *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift_imm_tl(ctx, a, EXT_NONE, gen_bclr);
 }
 
@@ -209,13 +214,13 @@ static void gen_binv(TCGv ret, TCGv arg1, TCGv shamt)
 
 static bool trans_binv(DisasContext *ctx, arg_binv *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift(ctx, a, EXT_NONE, gen_binv);
 }
 
 static bool trans_binvi(DisasContext *ctx, arg_binvi *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift_imm_tl(ctx, a, EXT_NONE, gen_binv);
 }
 
@@ -227,13 +232,13 @@ static void gen_bext(TCGv ret, TCGv arg1, TCGv shamt)
 
 static bool trans_bext(DisasContext *ctx, arg_bext *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift(ctx, a, EXT_NONE, gen_bext);
 }
 
 static bool trans_bexti(DisasContext *ctx, arg_bexti *a)
 {
-    REQUIRE_EXT(ctx, RVB);
+    REQUIRE_ZBS(ctx);
     return gen_shift_imm_tl(ctx, a, EXT_NONE, gen_bext);
 }