diff --git a/crates/oxide_compiler/src/compiler.rs b/crates/oxide_compiler/src/compiler.rs
index 992ad166..d5ebf6ea 100644
--- a/crates/oxide_compiler/src/compiler.rs
+++ b/crates/oxide_compiler/src/compiler.rs
@@ -340,6 +340,7 @@ impl Compiler {
                     BinaryOperator::GreaterThan => OpCode::GT,
                     BinaryOperator::LessEqualThan => OpCode::LTE,
                     BinaryOperator::GreaterEqualThan => OpCode::GTE,
+                    BinaryOperator::In => OpCode::IN,
                     _ => return Err(format!("unsupported binary operator: {:?}", bin.operator)),
                 };
                 let r = ctx.alloc_reg();
@@ -348,12 +349,23 @@ impl Compiler {
             }
             Expression::UnaryExpression(un) => {
                 let arg = self.emit_expression(&un.argument, ctx)?;
-                if matches!(un.operator, UnaryOperator::UnaryNegation) {
-                    let r = ctx.alloc_reg();
-                    ctx.emit(opcode::encode(OpCode::NEG, r, arg, 0));
-                    Ok(r)
-                } else {
-                    Err(format!("unsupported unary operator: {:?}", un.operator))
+                match un.operator {
+                    UnaryOperator::UnaryNegation => {
+                        let r = ctx.alloc_reg();
+                        ctx.emit(opcode::encode(OpCode::NEG, r, arg, 0));
+                        Ok(r)
+                    }
+                    UnaryOperator::Typeof => {
+                        let r = ctx.alloc_reg();
+                        ctx.emit(opcode::encode(OpCode::TYPEOF, r, arg, 0));
+                        Ok(r)
+                    }
+                    UnaryOperator::Void => {
+                        let r = ctx.alloc_reg();
+                        ctx.emit(opcode::encode(OpCode::VOID, r, arg, 0));
+                        Ok(r)
+                    }
+                    _ => Err(format!("unsupported unary operator: {:?}", un.operator)),
                 }
             }
             Expression::StaticMemberExpression(member) => {
diff --git a/crates/oxide_vm/src/vm.rs b/crates/oxide_vm/src/vm.rs
index cf8364b0..f1a91d3e 100644
--- a/crates/oxide_vm/src/vm.rs
+++ b/crates/oxide_vm/src/vm.rs
@@ -426,6 +426,51 @@ impl Vm {
                     }
                 }
 
+                OpCode::TYPEOF => {
+                    let val = self.regs[a];
+                    let result = if val.is_undefined() {
+                        "undefined"
+                    } else if val.is_null() {
+                        "object"
+                    } else if val.is_bool() {
+                        "boolean"
+                    } else if val.is_int() || val.is_double() {
+                        "number"
+                    } else if val.is_string() {
+                        "string"
+                    } else if val.is_object() {
+                        let obj = unsafe { &*val.as_js_object_ptr() };
+                        if obj.is_function() {
+                            "function"
+                        } else {
+                            "object"
+                        }
+                    } else {
+                        "undefined"
+                    };
+                    self.regs[rd] = self.intern(result);
+                }
+
+                OpCode::VOID => {
+                    self.regs[rd] = JsValue::undefined();
+                }
+
+                OpCode::IN => {
+                    let key_val = self.regs[a];
+                    let obj_ptr = self.regs[b].as_object_ptr() as *mut JsObject;
+                    if obj_ptr.is_null() {
+                        return Err("IN right-hand side is not an object".into());
+                    }
+                    let obj = unsafe { &*obj_ptr };
+                    let prop_name_si = if key_val.is_string() {
+                        key_val.as_string_index()
+                    } else {
+                        return Err("IN key must be a string".into());
+                    };
+                    let found = self.resolve_property(obj, prop_name_si).is_some();
+                    self.regs[rd] = JsValue::bool(found);
+                }
+
                 _ => {
                     if !op.is_implemented() {
                         return Ok(JsValue::undefined());