diff --git a/o1vm/src/interpreters/riscv32im/constraints.rs b/o1vm/src/interpreters/riscv32im/constraints.rs
index ba1633e1a7..e45099490e 100644
--- a/o1vm/src/interpreters/riscv32im/constraints.rs
+++ b/o1vm/src/interpreters/riscv32im/constraints.rs
@@ -77,8 +77,8 @@ impl<Fp: Field> InterpreterEnv for Env<Fp> {
         // No-op, witness only
     }
 
-    fn check_boolean(_x: &Self::Variable) {
-        // No-op, witness only
+    fn assert_boolean(&mut self, x: &Self::Variable) {
+        self.add_constraint(x.clone() * x.clone() - x.clone());
     }
 
     fn add_lookup(&mut self, lookup: Lookup<Self::Variable>) {
diff --git a/o1vm/src/interpreters/riscv32im/interpreter.rs b/o1vm/src/interpreters/riscv32im/interpreter.rs
index 8a3e02d022..0b0adab521 100644
--- a/o1vm/src/interpreters/riscv32im/interpreter.rs
+++ b/o1vm/src/interpreters/riscv32im/interpreter.rs
@@ -598,14 +598,8 @@ pub trait InterpreterEnv {
         self.add_constraint(x - y);
     }
 
-    /// Check that the witness value `x` is a boolean (`0` or `1`); otherwise abort.
-    fn check_boolean(x: &Self::Variable);
-
     /// Assert that the value `x` is boolean, and add a constraint in the proof system.
-    fn assert_boolean(&mut self, x: &Self::Variable) {
-        Self::check_boolean(x);
-        self.add_constraint(x.clone() * x.clone() - x.clone());
-    }
+    fn assert_boolean(&mut self, x: &Self::Variable);
 
     fn add_lookup(&mut self, lookup: Lookup<Self::Variable>);
 
diff --git a/o1vm/src/interpreters/riscv32im/witness.rs b/o1vm/src/interpreters/riscv32im/witness.rs
index 011185339b..256de81687 100644
--- a/o1vm/src/interpreters/riscv32im/witness.rs
+++ b/o1vm/src/interpreters/riscv32im/witness.rs
@@ -88,8 +88,8 @@ impl<Fp: Field> InterpreterEnv for Env<Fp> {
         assert_eq!(*x, *y);
     }
 
-    fn check_boolean(x: &Self::Variable) {
-        if !(*x == 0 || *x == 1) {
+    fn assert_boolean(&mut self, x: &Self::Variable) {
+        if *x != 0 && *x != 1 {
             panic!("The value {} is not a boolean", *x);
         }
     }