diff --git a/src/lib/exec.rs b/src/lib/exec.rs
index 19458ce4f63..7d45d1019fc 100644
--- a/src/lib/exec.rs
+++ b/src/lib/exec.rs
@@ -15,7 +15,10 @@ use crate::{
     },
 };
 use gc::{Gc, GcCell};
-use std::{borrow::Borrow, ops::Deref};
+use std::{
+    borrow::Borrow,
+    ops::{Deref, DerefMut},
+};
 
 /// An execution engine
 pub trait Executor {
@@ -470,7 +473,17 @@ impl Default for InterpreterBuilder {
 impl Interpreter {
     /// https://tc39.es/ecma262/#sec-call
     fn call(&mut self, f: &Value, v: &Value, arguments_list: Vec<Value>) -> ResultValue {
+        // All functions should be objects, and eventually will be.
+        // During this transition call will support both native functions and function objects
         match (*f).deref() {
+            ValueData::Object(ref obj) => {
+                let func: Value = obj.borrow_mut().deref_mut().get_internal_slot("call");
+                if !func.is_undefined() {
+                    return self.call(&func, v, arguments_list);
+                }
+                // TODO: error object should be here
+                Err(Gc::new(ValueData::Undefined))
+            }
             ValueData::Function(ref inner_func) => match *inner_func.deref().borrow() {
                 Function::NativeFunc(ref ntv) => {
                     let func = ntv.data;
diff --git a/src/lib/js/boolean.rs b/src/lib/js/boolean.rs
index 3c688785aa3..196284c2a89 100644
--- a/src/lib/js/boolean.rs
+++ b/src/lib/js/boolean.rs
@@ -100,6 +100,22 @@ mod tests {
         assert_eq!(boolean_constructor.is_function(), true);
     }
 
+    #[test]
+    /// Test the correct type is returned from call and construct
+    fn construct_and_call() {
+        let mut engine = Executor::new();
+        let init = r#"
+        const one = new Boolean(1);
+        const zero = Boolean(0);
+        "#;
+        forward(&mut engine, init);
+        let one = forward_val(&mut engine, "one").unwrap();
+        let zero = forward_val(&mut engine, "zero").unwrap();
+
+        assert_eq!(one.is_object(), true);
+        assert_eq!(zero.is_boolean(), true);
+    }
+
     #[test]
     fn constructor_gives_true_instance() {
         let mut engine = Executor::new();
diff --git a/src/lib/js/string.rs b/src/lib/js/string.rs
index 7442c082c16..2ac665d6ec6 100644
--- a/src/lib/js/string.rs
+++ b/src/lib/js/string.rs
@@ -7,12 +7,13 @@ use crate::{
         value::{from_value, to_value, ResultValue, Value, ValueData},
     },
 };
+use gc::Gc;
 use std::{
     cmp::{max, min},
     f64::NAN,
 };
 
-/// Create new string
+/// Create new string [[Construct]]
 /// <https://searchfox.org/mozilla-central/source/js/src/vm/StringObject.h#19>
 // This gets called when a new String() is created, it's called by exec:346
 pub fn make_string(this: &Value, args: &[Value], _: &mut Interpreter) -> ResultValue {
@@ -33,6 +34,21 @@ pub fn make_string(this: &Value, args: &[Value], _: &mut Interpreter) -> ResultV
     Ok(this.clone())
 }
 
+/// Call new string [[Call]]
+/// https://tc39.es/ecma262/#sec-string-constructor-string-value
+pub fn call_string(_: &Value, args: &[Value], _: &mut Interpreter) -> ResultValue {
+    let arg = match args.get(0) {
+        Some(v) => v.clone(),
+        None => Gc::new(ValueData::Undefined),
+    };
+
+    if arg.is_undefined() {
+        return Ok(to_value(""));
+    }
+
+    Ok(to_value(arg.to_string()))
+}
+
 /// Get a string's length
 pub fn get_string_length(this: &Value, _: &[Value], ctx: &mut Interpreter) -> ResultValue {
     let this_str = ctx.value_to_rust_string(this);
@@ -654,7 +670,7 @@ pub fn create_constructor(global: &Value) -> Value {
     string_constructor.set_internal_method("construct", make_string);
     // Todo: add call internal method (should be easy)
     // Currently call points to the constructor function, this is wrong
-    string_constructor.set_internal_method("call", make_string);
+    string_constructor.set_internal_method("call", call_string);
 
     // Create prototype
     let proto = ValueData::new_obj(Some(global));
@@ -697,7 +713,7 @@ pub fn init(global: &Value) {
 mod tests {
     use super::*;
     use crate::exec::Executor;
-    use crate::forward;
+    use crate::{forward, forward_val};
 
     #[test]
     fn check_string_constructor_is_function() {
@@ -747,6 +763,22 @@ mod tests {
         //assert_eq!(b, String::from("Hello, world! Have a nice day."));
     }
 
+    #[test]
+    /// Test the correct type is returned from call and construct
+    fn construct_and_call() {
+        let mut engine = Executor::new();
+        let init = r#"
+        const hello = new String('Hello');
+        const world = String('world');
+        "#;
+        forward(&mut engine, init);
+        let hello = forward_val(&mut engine, "hello").unwrap();
+        let world = forward_val(&mut engine, "world").unwrap();
+
+        assert_eq!(hello.is_object(), true);
+        assert_eq!(world.is_string(), true);
+    }
+
     #[test]
     fn repeat() {
         let mut engine = Executor::new();
diff --git a/src/lib/js/value.rs b/src/lib/js/value.rs
index e896fb0780b..a0bd6990357 100644
--- a/src/lib/js/value.rs
+++ b/src/lib/js/value.rs
@@ -139,6 +139,14 @@ impl ValueData {
         }
     }
 
+    /// Returns true if the value is a boolean
+    pub fn is_boolean(&self) -> bool {
+        match *self {
+            ValueData::Boolean(_) => true,
+            _ => false,
+        }
+    }
+
     /// Returns true if the value is true
     /// [toBoolean](https://tc39.github.io/ecma262/#sec-toboolean)
     pub fn is_true(&self) -> bool {
diff --git a/tests/js/test.js b/tests/js/test.js
index b895dfad009..c990b090bbf 100644
--- a/tests/js/test.js
+++ b/tests/js/test.js
@@ -1,4 +1,2 @@
-function jason(a, b) {
-  return arguments[0];
-}
-const val = jason(100, 6);
+let a = Boolean(0);
+typeof a;