diff --git a/evm/src/cpu/cpu_stark.rs b/evm/src/cpu/cpu_stark.rs
index d922c473..09c7d576 100644
--- a/evm/src/cpu/cpu_stark.rs
+++ b/evm/src/cpu/cpu_stark.rs
@@ -146,7 +146,7 @@ impl<F: RichField + Extendable<D>, const D: usize> Stark<F, D> for CpuStark<F, D
         bootstrap_kernel::eval_bootstrap_kernel(vars, yield_constr);
         contextops::eval_packed(local_values, next_values, yield_constr);
         control_flow::eval_packed_generic(local_values, next_values, yield_constr);
-        decode::eval_packed_generic(local_values, &mut dummy_yield_constr);
+        decode::eval_packed_generic(local_values, yield_constr);
         dup_swap::eval_packed(local_values, yield_constr);
         gas::eval_packed(local_values, next_values, yield_constr);
         jumps::eval_packed(local_values, next_values, yield_constr);
@@ -176,7 +176,7 @@ impl<F: RichField + Extendable<D>, const D: usize> Stark<F, D> for CpuStark<F, D
         bootstrap_kernel::eval_bootstrap_kernel_circuit(builder, vars, yield_constr);
         contextops::eval_ext_circuit(builder, local_values, next_values, yield_constr);
         control_flow::eval_ext_circuit(builder, local_values, next_values, yield_constr);
-        decode::eval_ext_circuit(builder, local_values, &mut dummy_yield_constr);
+        decode::eval_ext_circuit(builder, local_values, yield_constr);
         dup_swap::eval_ext_circuit(builder, local_values, yield_constr);
         gas::eval_ext_circuit(builder, local_values, next_values, yield_constr);
         jumps::eval_ext_circuit(builder, local_values, next_values, yield_constr);
diff --git a/evm/src/cpu/decode.rs b/evm/src/cpu/decode.rs
index 5ce3979a..c6f6e1ed 100644
--- a/evm/src/cpu/decode.rs
+++ b/evm/src/cpu/decode.rs
@@ -191,7 +191,7 @@ pub fn eval_packed_generic<P: PackedField>(
             .into_iter()
             .zip(bits_from_opcode(oc))
             .rev()
-            .take(block_length + 1)
+            .take(8 - block_length)
             .map(|(row_bit, flag_bit)| match flag_bit {
                 // 1 if the bit does not match, and 0 otherwise
                 false => row_bit,
@@ -264,7 +264,7 @@ pub fn eval_ext_circuit<F: RichField + Extendable<D>, const D: usize>(
             .into_iter()
             .zip(bits_from_opcode(oc))
             .rev()
-            .take(block_length + 1)
+            .take(8 - block_length)
             .fold(builder.zero_extension(), |cumul, (row_bit, flag_bit)| {
                 let to_add = match flag_bit {
                     false => row_bit,