diff --git a/boa/src/builtins/array_buffer/mod.rs b/boa/src/builtins/array_buffer/mod.rs
index 21d27ee457..8ac9d29fc7 100644
--- a/boa/src/builtins/array_buffer/mod.rs
+++ b/boa/src/builtins/array_buffer/mod.rs
@@ -307,7 +307,7 @@ impl ArrayBuffer {
             context,
         )?;
         let obj = context.construct_object();
-        obj.set_prototype_instance(prototype.into());
+        obj.set_prototype(prototype.into());
 
         // 2. Let block be ? CreateByteDataBlock(byteLength).
         // TODO: for now just a arbitrary limit to not OOM.
diff --git a/boa/src/builtins/boolean/tests.rs b/boa/src/builtins/boolean/tests.rs
index b97fa65ea3..57360aae7a 100644
--- a/boa/src/builtins/boolean/tests.rs
+++ b/boa/src/builtins/boolean/tests.rs
@@ -1,4 +1,4 @@
-use crate::{forward, forward_val, Context, JsValue};
+use crate::{forward, forward_val, Context};
 
 /// Test the correct type is returned from call and construct
 #[allow(clippy::unwrap_used)]
@@ -58,8 +58,8 @@ fn instances_have_correct_proto_set() {
     let bool_instance = forward_val(&mut context, "boolInstance").expect("value expected");
     let bool_prototype = forward_val(&mut context, "boolProto").expect("value expected");
 
-    assert!(JsValue::same_value(
-        &bool_instance.as_object().unwrap().prototype_instance(),
-        &bool_prototype
-    ));
+    assert_eq!(
+        &*bool_instance.as_object().unwrap().prototype(),
+        &bool_prototype.as_object()
+    );
 }
diff --git a/boa/src/builtins/console/mod.rs b/boa/src/builtins/console/mod.rs
index 06ba2cd9f1..3f074091de 100644
--- a/boa/src/builtins/console/mod.rs
+++ b/boa/src/builtins/console/mod.rs
@@ -568,7 +568,6 @@ impl Console {
             LogMessage::Info(display_obj(args.get_or_undefined(0), true)),
             context.console(),
         );
-
         Ok(JsValue::undefined())
     }
 }
diff --git a/boa/src/builtins/error/eval.rs b/boa/src/builtins/error/eval.rs
index bd941a0c04..2c86ca61f2 100644
--- a/boa/src/builtins/error/eval.rs
+++ b/boa/src/builtins/error/eval.rs
@@ -46,7 +46,7 @@ impl BuiltIn for EvalError {
         )
         .name(Self::NAME)
         .length(Self::LENGTH)
-        .inherit(error_prototype.into())
+        .inherit(error_prototype)
         .property("name", Self::NAME, attribute)
         .property("message", "", attribute)
         .build();
diff --git a/boa/src/builtins/error/range.rs b/boa/src/builtins/error/range.rs
index 1b62980b24..090c8f7f4c 100644
--- a/boa/src/builtins/error/range.rs
+++ b/boa/src/builtins/error/range.rs
@@ -43,7 +43,7 @@ impl BuiltIn for RangeError {
         )
         .name(Self::NAME)
         .length(Self::LENGTH)
-        .inherit(error_prototype.into())
+        .inherit(error_prototype)
         .property("name", Self::NAME, attribute)
         .property("message", "", attribute)
         .build();
diff --git a/boa/src/builtins/error/reference.rs b/boa/src/builtins/error/reference.rs
index 663fee744c..e0afa38d36 100644
--- a/boa/src/builtins/error/reference.rs
+++ b/boa/src/builtins/error/reference.rs
@@ -42,7 +42,7 @@ impl BuiltIn for ReferenceError {
         )
         .name(Self::NAME)
         .length(Self::LENGTH)
-        .inherit(error_prototype.into())
+        .inherit(error_prototype)
         .property("name", Self::NAME, attribute)
         .property("message", "", attribute)
         .build();
diff --git a/boa/src/builtins/error/syntax.rs b/boa/src/builtins/error/syntax.rs
index 027fd040d0..a5e18262e6 100644
--- a/boa/src/builtins/error/syntax.rs
+++ b/boa/src/builtins/error/syntax.rs
@@ -45,7 +45,7 @@ impl BuiltIn for SyntaxError {
         )
         .name(Self::NAME)
         .length(Self::LENGTH)
-        .inherit(error_prototype.into())
+        .inherit(error_prototype)
         .property("name", Self::NAME, attribute)
         .property("message", "", attribute)
         .build();
diff --git a/boa/src/builtins/error/type.rs b/boa/src/builtins/error/type.rs
index 5a42856d9e..ddc47fd369 100644
--- a/boa/src/builtins/error/type.rs
+++ b/boa/src/builtins/error/type.rs
@@ -48,7 +48,7 @@ impl BuiltIn for TypeError {
         )
         .name(Self::NAME)
         .length(Self::LENGTH)
-        .inherit(error_prototype.into())
+        .inherit(error_prototype)
         .property("name", Self::NAME, attribute)
         .property("message", "", attribute)
         .build();
diff --git a/boa/src/builtins/error/uri.rs b/boa/src/builtins/error/uri.rs
index b90c8934e9..07e600712e 100644
--- a/boa/src/builtins/error/uri.rs
+++ b/boa/src/builtins/error/uri.rs
@@ -44,7 +44,7 @@ impl BuiltIn for UriError {
         )
         .name(Self::NAME)
         .length(Self::LENGTH)
-        .inherit(error_prototype.into())
+        .inherit(error_prototype)
         .property("name", Self::NAME, attribute)
         .property("message", "", attribute)
         .build();
diff --git a/boa/src/builtins/json/tests.rs b/boa/src/builtins/json/tests.rs
index 8a2f2dc1cd..1cc126580d 100644
--- a/boa/src/builtins/json/tests.rs
+++ b/boa/src/builtins/json/tests.rs
@@ -1,4 +1,4 @@
-use crate::{forward, forward_val, Context, JsValue};
+use crate::{forward, forward_val, Context};
 
 #[test]
 fn json_sanity() {
@@ -413,27 +413,22 @@ fn json_parse_sets_prototypes() {
         .unwrap()
         .as_object()
         .unwrap()
-        .prototype_instance();
+        .prototype()
+        .clone();
     let array_prototype = forward_val(&mut context, r#"jsonObj.arr"#)
         .unwrap()
         .as_object()
         .unwrap()
-        .prototype_instance();
-    let global_object_prototype: JsValue = context
+        .prototype()
+        .clone();
+    let global_object_prototype = context
         .standard_objects()
         .object_object()
         .prototype()
         .into();
-    let global_array_prototype: JsValue =
-        context.standard_objects().array_object().prototype().into();
-    assert!(JsValue::same_value(
-        &object_prototype,
-        &global_object_prototype
-    ));
-    assert!(JsValue::same_value(
-        &array_prototype,
-        &global_array_prototype
-    ));
+    let global_array_prototype = context.standard_objects().array_object().prototype().into();
+    assert_eq!(object_prototype, global_object_prototype);
+    assert_eq!(array_prototype, global_array_prototype);
 }
 
 #[test]
diff --git a/boa/src/builtins/object/for_in_iterator.rs b/boa/src/builtins/object/for_in_iterator.rs
index dc85030d6c..6289208051 100644
--- a/boa/src/builtins/object/for_in_iterator.rs
+++ b/boa/src/builtins/object/for_in_iterator.rs
@@ -98,8 +98,9 @@ impl ForInIterator {
                             }
                         }
                     }
-                    match object.prototype_instance().to_object(context) {
-                        Ok(o) => {
+                    let proto = object.prototype().clone();
+                    match proto {
+                        Some(o) => {
                             object = o;
                         }
                         _ => {
diff --git a/boa/src/builtins/object/mod.rs b/boa/src/builtins/object/mod.rs
index fd901975c4..255a260e11 100644
--- a/boa/src/builtins/object/mod.rs
+++ b/boa/src/builtins/object/mod.rs
@@ -22,7 +22,7 @@ use crate::{
     },
     property::{Attribute, DescriptorKind, PropertyDescriptor, PropertyKey, PropertyNameKind},
     symbol::WellKnownSymbols,
-    value::{JsValue, Type},
+    value::JsValue,
     BoaProfiler, Context, JsResult,
 };
 
@@ -53,7 +53,7 @@ impl BuiltIn for Object {
         )
         .name(Self::NAME)
         .length(Self::LENGTH)
-        .inherit(JsValue::null())
+        .inherit(None)
         .method(Self::has_own_property, "hasOwnProperty", 0)
         .method(Self::property_is_enumerable, "propertyIsEnumerable", 0)
         .method(Self::to_string, "toString", 0)
@@ -284,7 +284,9 @@ impl Object {
         let obj = args[0].clone().to_object(ctx)?;
 
         // 2. Return ? obj.[[GetPrototypeOf]]().
-        Ok(obj.prototype_instance())
+        Ok(obj
+            .__get_prototype_of__(ctx)?
+            .map_or(JsValue::Null, JsValue::new))
     }
 
     /// Set the `prototype` of an object.
@@ -301,32 +303,32 @@ impl Object {
         }
 
         // 1. Set O to ? RequireObjectCoercible(O).
-        let obj = args
+        let o = args
             .get(0)
             .cloned()
             .unwrap_or_default()
             .require_object_coercible(ctx)?
             .clone();
 
-        // 2. If Type(proto) is neither Object nor Null, throw a TypeError exception.
-        let proto = args.get_or_undefined(1);
-        if !matches!(proto.get_type(), Type::Object | Type::Null) {
-            return ctx.throw_type_error(format!(
-                "expected an object or null, got {}",
-                proto.type_of()
-            ));
-        }
+        let proto = match args.get_or_undefined(1) {
+            JsValue::Object(obj) => Some(obj.clone()),
+            JsValue::Null => None,
+            // 2. If Type(proto) is neither Object nor Null, throw a TypeError exception.
+            val => {
+                return ctx
+                    .throw_type_error(format!("expected an object or null, got {}", val.type_of()))
+            }
+        };
 
-        // 3. If Type(O) is not Object, return O.
-        if !obj.is_object() {
-            return Ok(obj);
-        }
+        let mut obj = if let Some(obj) = o.as_object() {
+            obj
+        } else {
+            // 3. If Type(O) is not Object, return O.
+            return Ok(o);
+        };
 
         // 4. Let status be ? O.[[SetPrototypeOf]](proto).
-        let status = obj
-            .as_object()
-            .expect("obj was not an object")
-            .__set_prototype_of__(proto.clone(), ctx)?;
+        let status = obj.__set_prototype_of__(proto, ctx)?;
 
         // 5. If status is false, throw a TypeError exception.
         if !status {
@@ -334,7 +336,7 @@ impl Object {
         }
 
         // 6. Return O.
-        Ok(obj)
+        Ok(o)
     }
 
     /// `Object.prototype.isPrototypeOf( proto )`
diff --git a/boa/src/builtins/reflect/mod.rs b/boa/src/builtins/reflect/mod.rs
index 7bed5e6de7..9982831cea 100644
--- a/boa/src/builtins/reflect/mod.rs
+++ b/boa/src/builtins/reflect/mod.rs
@@ -244,7 +244,9 @@ impl Reflect {
             .get(0)
             .and_then(|v| v.as_object())
             .ok_or_else(|| context.construct_type_error("target must be an object"))?;
-        target.__get_prototype_of__(context)
+        Ok(target
+            .__get_prototype_of__(context)?
+            .map_or(JsValue::Null, JsValue::new))
     }
 
     /// Returns `true` if the object has the property, `false` otherwise.
@@ -377,10 +379,11 @@ impl Reflect {
             .get(0)
             .and_then(|v| v.as_object())
             .ok_or_else(|| context.construct_type_error("target must be an object"))?;
-        let proto = args.get_or_undefined(1);
-        if !proto.is_null() && !proto.is_object() {
-            return context.throw_type_error("proto must be an object or null");
-        }
-        Ok(target.__set_prototype_of__(proto.clone(), context)?.into())
+        let proto = match args.get_or_undefined(1) {
+            JsValue::Object(obj) => Some(obj.clone()),
+            JsValue::Null => None,
+            _ => return context.throw_type_error("proto must be an object or null"),
+        };
+        Ok(target.__set_prototype_of__(proto, context)?.into())
     }
 }
diff --git a/boa/src/builtins/typed_array/integer_indexed_object.rs b/boa/src/builtins/typed_array/integer_indexed_object.rs
index 4541581d60..e4b7ab066f 100644
--- a/boa/src/builtins/typed_array/integer_indexed_object.rs
+++ b/boa/src/builtins/typed_array/integer_indexed_object.rs
@@ -77,7 +77,7 @@ impl IntegerIndexed {
         a.borrow_mut().data = ObjectData::integer_indexed(data);
 
         // 10. Set A.[[Prototype]] to prototype.
-        a.set_prototype_instance(prototype.into());
+        a.set_prototype(prototype.into());
 
         // 11. Return A.
         a
diff --git a/boa/src/builtins/typed_array/mod.rs b/boa/src/builtins/typed_array/mod.rs
index a3ea0cc57a..bdaba5b9db 100644
--- a/boa/src/builtins/typed_array/mod.rs
+++ b/boa/src/builtins/typed_array/mod.rs
@@ -82,8 +82,8 @@ macro_rules! typed_array {
                     TypedArrayName::$ty.element_size(),
                     Attribute::READONLY | Attribute::NON_ENUMERABLE | Attribute::PERMANENT,
                 )
-                .custom_prototype(typed_array_constructor.into())
-                .inherit(typed_array_constructor_proto.into())
+                .custom_prototype(typed_array_constructor)
+                .inherit(typed_array_constructor_proto)
                 .build()
                 .into()
             }
diff --git a/boa/src/environment/function_environment_record.rs b/boa/src/environment/function_environment_record.rs
index 68ebef144e..2d7262e660 100644
--- a/boa/src/environment/function_environment_record.rs
+++ b/boa/src/environment/function_environment_record.rs
@@ -17,7 +17,7 @@ use crate::{
         lexical_environment::{Environment, EnvironmentType, VariableScope},
     },
     gc::{empty_trace, Finalize, Trace},
-    object::JsObject,
+    object::{JsObject, JsPrototype},
     Context, JsResult, JsValue,
 };
 
@@ -114,21 +114,23 @@ impl FunctionEnvironmentRecord {
     ///  - [ECMAScript reference][spec]
     ///
     /// [spec]: https://tc39.es/ecma262/#sec-getsuperbase
-    pub fn get_super_base(&self) -> JsValue {
+    pub fn get_super_base(&self, context: &mut Context) -> JsResult<Option<JsPrototype>> {
         // 1. Let home be envRec.[[FunctionObject]].[[HomeObject]].
         let home = &self.home_object;
 
         // 2. If home has the value undefined, return undefined.
         if home.is_undefined() {
-            JsValue::undefined()
+            Ok(None)
         } else {
             // 3. Assert: Type(home) is Object.
             assert!(home.is_object());
 
             // 4. Return ? home.[[GetPrototypeOf]]().
-            home.as_object()
-                .expect("home_object must be an Object")
-                .prototype_instance()
+            Ok(Some(
+                home.as_object()
+                    .expect("home_object must be an Object")
+                    .__get_prototype_of__(context)?,
+            ))
         }
     }
 }
diff --git a/boa/src/exec/tests.rs b/boa/src/exec/tests.rs
index 217fc214e0..6439e4c9cf 100644
--- a/boa/src/exec/tests.rs
+++ b/boa/src/exec/tests.rs
@@ -791,9 +791,12 @@ mod in_operator {
         let bar_val = forward_val(&mut context, "bar").unwrap();
         let bar_obj = bar_val.as_object().unwrap();
         let foo_val = forward_val(&mut context, "Foo").unwrap();
-        assert!(bar_obj
-            .prototype_instance()
-            .strict_equals(&foo_val.get_field("prototype", &mut context).unwrap()));
+        assert_eq!(
+            &*bar_obj.prototype(),
+            &foo_val
+                .as_object()
+                .and_then(|obj| obj.get("prototype", &mut context).unwrap().as_object())
+        );
     }
 }
 
diff --git a/boa/src/object/internal_methods/mod.rs b/boa/src/object/internal_methods/mod.rs
index 4c5cf7b085..abdfd355eb 100644
--- a/boa/src/object/internal_methods/mod.rs
+++ b/boa/src/object/internal_methods/mod.rs
@@ -13,7 +13,7 @@ use crate::{
     BoaProfiler, Context, JsResult,
 };
 
-use super::PROTOTYPE;
+use super::{JsPrototype, PROTOTYPE};
 
 pub(super) mod arguments;
 pub(super) mod array;
@@ -31,7 +31,7 @@ impl JsObject {
     /// [spec]: https://tc39.es/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots-getprototypeof
     #[inline]
     #[track_caller]
-    pub(crate) fn __get_prototype_of__(&self, context: &mut Context) -> JsResult<JsValue> {
+    pub(crate) fn __get_prototype_of__(&self, context: &mut Context) -> JsResult<JsPrototype> {
         let func = self.borrow().data.internal_methods.__get_prototype_of__;
         func(self, context)
     }
@@ -47,7 +47,7 @@ impl JsObject {
     #[inline]
     pub(crate) fn __set_prototype_of__(
         &mut self,
-        val: JsValue,
+        val: JsPrototype,
         context: &mut Context,
     ) -> JsResult<bool> {
         let func = self.borrow().data.internal_methods.__set_prototype_of__;
@@ -245,8 +245,8 @@ pub(crate) static ORDINARY_INTERNAL_METHODS: InternalObjectMethods = InternalObj
 /// For a guide on how to implement exotic internal methods, see `ORDINARY_INTERNAL_METHODS`.
 #[derive(Clone, Copy)]
 pub(crate) struct InternalObjectMethods {
-    pub(crate) __get_prototype_of__: fn(&JsObject, &mut Context) -> JsResult<JsValue>,
-    pub(crate) __set_prototype_of__: fn(&JsObject, JsValue, &mut Context) -> JsResult<bool>,
+    pub(crate) __get_prototype_of__: fn(&JsObject, &mut Context) -> JsResult<JsPrototype>,
+    pub(crate) __set_prototype_of__: fn(&JsObject, JsPrototype, &mut Context) -> JsResult<bool>,
     pub(crate) __is_extensible__: fn(&JsObject, &mut Context) -> JsResult<bool>,
     pub(crate) __prevent_extensions__: fn(&JsObject, &mut Context) -> JsResult<bool>,
     pub(crate) __get_own_property__:
@@ -271,9 +271,9 @@ pub(crate) struct InternalObjectMethods {
 pub(crate) fn ordinary_get_prototype_of(
     obj: &JsObject,
     _context: &mut Context,
-) -> JsResult<JsValue> {
+) -> JsResult<JsPrototype> {
     // 1. Return O.[[Prototype]].
-    Ok(obj.borrow().prototype.clone())
+    Ok(obj.prototype().as_ref().cloned())
 }
 
 /// Abstract operation `OrdinarySetPrototypeOf`.
@@ -285,23 +285,23 @@ pub(crate) fn ordinary_get_prototype_of(
 #[inline]
 pub(crate) fn ordinary_set_prototype_of(
     obj: &JsObject,
-    val: JsValue,
-    context: &mut Context,
+    val: JsPrototype,
+    _: &mut Context,
 ) -> JsResult<bool> {
     // 1. Assert: Either Type(V) is Object or Type(V) is Null.
-    debug_assert!(val.is_object() || val.is_null());
+    {
+        // 2. Let current be O.[[Prototype]].
+        let current = obj.prototype();
 
-    // 2. Let current be O.[[Prototype]].
-    let current = obj.__get_prototype_of__(context)?;
-
-    // 3. If SameValue(V, current) is true, return true.
-    if JsValue::same_value(&current, &val) {
-        return Ok(true);
+        // 3. If SameValue(V, current) is true, return true.
+        if val == *current {
+            return Ok(true);
+        }
     }
 
     // 4. Let extensible be O.[[Extensible]].
     // 5. If extensible is false, return false.
-    if !obj.__is_extensible__(context)? {
+    if !obj.extensible() {
         return Ok(false);
     }
 
@@ -309,37 +309,29 @@ pub(crate) fn ordinary_set_prototype_of(
     let mut p = val.clone();
 
     // 7. Let done be false.
-    let mut done = false;
-
     // 8. Repeat, while done is false,
-    while !done {
-        match p {
-            // a. If p is null, set done to true.
-            JsValue::Null => done = true,
-            JsValue::Object(ref proto) => {
-                // b. Else if SameValue(p, O) is true, return false.
-                if JsObject::equals(proto, obj) {
-                    return Ok(false);
-                }
-                // c. Else,
-                // i. If p.[[GetPrototypeOf]] is not the ordinary object internal method defined
-                // in 10.1.1, set done to true.
-                else if proto.borrow().data.internal_methods.__get_prototype_of__ as usize
-                    != ordinary_get_prototype_of as usize
-                {
-                    done = true;
-                }
-                // ii. Else, set p to p.[[Prototype]].
-                else {
-                    p = proto.__get_prototype_of__(context)?;
-                }
-            }
-            _ => unreachable!(),
+    // a. If p is null, set done to true.
+    while let Some(proto) = p {
+        // b. Else if SameValue(p, O) is true, return false.
+        if &proto == obj {
+            return Ok(false);
+        }
+        // c. Else,
+        // i. If p.[[GetPrototypeOf]] is not the ordinary object internal method defined
+        // in 10.1.1, set done to true.
+        else if proto.borrow().data.internal_methods.__get_prototype_of__ as usize
+            != ordinary_get_prototype_of as usize
+        {
+            break;
+        }
+        // ii. Else, set p to p.[[Prototype]].
+        else {
+            p = proto.prototype().clone();
         }
     }
 
     // 9. Set O.[[Prototype]] to V.
-    obj.borrow_mut().prototype = val;
+    obj.set_prototype(val);
 
     // 10. Return true.
     Ok(true)
@@ -454,7 +446,7 @@ pub(crate) fn ordinary_has_property(
         let parent = obj.__get_prototype_of__(context)?;
 
         // 5. If parent is not null, then
-        if let JsValue::Object(ref object) = parent {
+        if let Some(object) = parent {
             // a. Return ? parent.[[HasProperty]](P).
             object.__has_property__(key, context)
         } else {
@@ -483,7 +475,7 @@ pub(crate) fn ordinary_get(
         // If desc is undefined, then
         None => {
             // a. Let parent be ? O.[[GetPrototypeOf]]().
-            if let Some(parent) = obj.__get_prototype_of__(context)?.as_object() {
+            if let Some(parent) = obj.__get_prototype_of__(context)? {
                 // c. Return ? parent.[[Get]](P, Receiver).
                 parent.__get__(key, receiver, context)
             }
@@ -537,7 +529,7 @@ pub(crate) fn ordinary_set(
     // 2. If ownDesc is undefined, then
     // a. Let parent be ? O.[[GetPrototypeOf]]().
     // b. If parent is not null, then
-    else if let Some(ref mut parent) = obj.__get_prototype_of__(context)?.as_object() {
+    else if let Some(parent) = obj.__get_prototype_of__(context)? {
         // i. Return ? parent.[[Set]](P, V, Receiver).
         return parent.__set__(key, value, receiver, context);
     }
diff --git a/boa/src/object/jsobject.rs b/boa/src/object/jsobject.rs
index 68d3f05e82..a881cf3e2c 100644
--- a/boa/src/object/jsobject.rs
+++ b/boa/src/object/jsobject.rs
@@ -2,7 +2,7 @@
 //!
 //! The `JsObject` is a garbage collected Object.
 
-use super::{NativeObject, Object};
+use super::{JsPrototype, NativeObject, Object};
 use crate::{
     object::{ObjectData, ObjectKind},
     property::{PropertyDescriptor, PropertyKey},
@@ -40,21 +40,6 @@ pub type RefMut<'a, T, U> = GcCellRefMut<'a, T, U>;
 #[derive(Trace, Finalize, Clone, Default)]
 pub struct JsObject(Gc<GcCell<Object>>);
 
-/// The body of a JavaScript function.
-///
-/// This is needed for the call method since we cannot mutate the function itself since we
-/// already borrow it so we get the function body clone it then drop the borrow and run the body
-#[cfg(not(feature = "vm"))]
-enum FunctionBody {
-    BuiltInFunction(NativeFunctionSignature),
-    BuiltInConstructor(NativeFunctionSignature),
-    Closure {
-        function: Box<dyn ClosureFunctionSignature>,
-        captures: Captures,
-    },
-    Ordinary(RcStatementList),
-}
-
 impl JsObject {
     /// Create a new `JsObject` from an internal `Object`.
     #[inline]
@@ -76,7 +61,7 @@ impl JsObject {
     pub fn from_proto_and_data<O: Into<Option<JsObject>>>(prototype: O, data: ObjectData) -> Self {
         Self::from_object(Object {
             data,
-            prototype: prototype.into().map_or(JsValue::Null, JsValue::new),
+            prototype: prototype.into(),
             extensible: true,
             properties: Default::default(),
         })
@@ -160,6 +145,21 @@ impl JsObject {
 
         use super::internal_methods::get_prototype_from_constructor;
 
+        /// The body of a JavaScript function.
+        ///
+        /// This is needed for the call method since we cannot mutate the function itself since we
+        /// already borrow it so we get the function body clone it then drop the borrow and run the body
+        #[cfg(not(feature = "vm"))]
+        enum FunctionBody {
+            BuiltInFunction(NativeFunctionSignature),
+            BuiltInConstructor(NativeFunctionSignature),
+            Closure {
+                function: Box<dyn ClosureFunctionSignature>,
+                captures: Captures,
+            },
+            Ordinary(RcStatementList),
+        }
+
         let this_function_object = self.clone();
         let mut has_parameter_expressions = false;
 
@@ -515,8 +515,18 @@ impl JsObject {
     /// Panics if the object is currently mutably borrowed.
     #[inline]
     #[track_caller]
-    pub fn prototype_instance(&self) -> JsValue {
-        self.borrow().prototype_instance().clone()
+    pub fn prototype(&self) -> Ref<'_, JsPrototype> {
+        Ref::map(self.borrow(), |obj| obj.prototype())
+    }
+
+    /// Get the extensibility of the object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    pub(crate) fn extensible(&self) -> bool {
+        self.borrow().extensible
     }
 
     /// Set the prototype of the object.
@@ -524,11 +534,10 @@ impl JsObject {
     /// # Panics
     ///
     /// Panics if the object is currently mutably borrowed
-    /// or if th prototype is not an object or undefined.
     #[inline]
     #[track_caller]
-    pub fn set_prototype_instance(&self, prototype: JsValue) -> bool {
-        self.borrow_mut().set_prototype_instance(prototype)
+    pub fn set_prototype(&self, prototype: JsPrototype) -> bool {
+        self.borrow_mut().set_prototype(prototype)
     }
 
     /// Checks if it's an `Array` object.
@@ -726,9 +735,9 @@ impl JsObject {
                 //      a. Set O to ? O.[[GetPrototypeOf]]().
                 //      b. If O is null, return false.
                 let mut object = object.__get_prototype_of__(context)?;
-                while let Some(object_prototype) = object.as_object() {
+                while let Some(object_prototype) = object {
                     //     c. If SameValue(P, O) is true, return true.
-                    if JsObject::equals(&prototype, &object_prototype) {
+                    if prototype == object_prototype {
                         return Ok(true);
                     }
                     // a. Set O to ? O.[[GetPrototypeOf]]().
@@ -972,6 +981,12 @@ impl AsRef<GcCell<Object>> for JsObject {
     }
 }
 
+impl PartialEq for JsObject {
+    fn eq(&self, other: &Self) -> bool {
+        JsObject::equals(self, other)
+    }
+}
+
 /// An error returned by [`JsObject::try_borrow`](struct.JsObject.html#method.try_borrow).
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct BorrowError;
diff --git a/boa/src/object/mod.rs b/boa/src/object/mod.rs
index 261d02591b..00c93fb065 100644
--- a/boa/src/object/mod.rs
+++ b/boa/src/object/mod.rs
@@ -49,6 +49,8 @@ use self::internal_methods::{
 /// Static `prototype`, usually set on constructors as a key to point to their respective prototype object.
 pub static PROTOTYPE: &str = "prototype";
 
+pub type JsPrototype = Option<JsObject>;
+
 /// This trait allows Rust types to be passed around as objects.
 ///
 /// This is automatically implemented, when a type implements `Debug`, `Any` and `Trace`.
@@ -72,14 +74,15 @@ impl<T: Any + Debug + Trace> NativeObject for T {
     }
 }
 
-/// The internal representation of an JavaScript object.
+/// The internal representation of a JavaScript object.
 #[derive(Debug, Trace, Finalize)]
 pub struct Object {
     /// The type of the object.
     pub data: ObjectData,
+    /// The collection of properties contained in the object
     properties: PropertyMap,
     /// Instance prototype `__proto__`.
-    prototype: JsValue,
+    prototype: JsPrototype,
     /// Whether it can have new properties added to it.
     extensible: bool,
 }
@@ -365,7 +368,7 @@ impl Default for Object {
         Self {
             data: ObjectData::ordinary(),
             properties: PropertyMap::default(),
-            prototype: JsValue::null(),
+            prototype: None,
             extensible: true,
         }
     }
@@ -936,7 +939,7 @@ impl Object {
 
     /// Gets the prototype instance of this object.
     #[inline]
-    pub fn prototype_instance(&self) -> &JsValue {
+    pub fn prototype(&self) -> &JsPrototype {
         &self.prototype
     }
 
@@ -947,15 +950,15 @@ impl Object {
     /// [spec]: https://tc39.es/ecma262/#sec-invariants-of-the-essential-internal-methods
     #[inline]
     #[track_caller]
-    pub fn set_prototype_instance(&mut self, prototype: JsValue) -> bool {
-        assert!(prototype.is_null() || prototype.is_object());
+    pub fn set_prototype<O: Into<JsPrototype>>(&mut self, prototype: O) -> bool {
+        let prototype = prototype.into();
         if self.extensible {
             self.prototype = prototype;
             true
         } else {
             // If target is non-extensible, [[SetPrototypeOf]] must return false
             // unless V is the SameValue as the target's observed [[GetPrototypeOf]] value.
-            JsValue::same_value(&prototype, &self.prototype)
+            self.prototype == prototype
         }
     }
 
@@ -1264,13 +1267,7 @@ impl<'context> FunctionBuilder<'context> {
     pub(crate) fn build_function_prototype(&mut self, object: &JsObject) {
         let mut object = object.borrow_mut();
         object.data = ObjectData::function(self.function.take().unwrap());
-        object.set_prototype_instance(
-            self.context
-                .standard_objects()
-                .object_object()
-                .prototype()
-                .into(),
-        );
+        object.set_prototype(self.context.standard_objects().object_object().prototype());
 
         let property = PropertyDescriptor::builder()
             .writable(false)
@@ -1387,8 +1384,8 @@ pub struct ConstructorBuilder<'context> {
     length: usize,
     callable: bool,
     constructable: bool,
-    inherit: Option<JsValue>,
-    custom_prototype: Option<JsValue>,
+    inherit: Option<JsPrototype>,
+    custom_prototype: Option<JsPrototype>,
 }
 
 impl Debug for ConstructorBuilder<'_> {
@@ -1642,9 +1639,8 @@ impl<'context> ConstructorBuilder<'context> {
     ///
     /// Default is `Object.prototype`
     #[inline]
-    pub fn inherit(&mut self, prototype: JsValue) -> &mut Self {
-        assert!(prototype.is_object() || prototype.is_null());
-        self.inherit = Some(prototype);
+    pub fn inherit<O: Into<JsPrototype>>(&mut self, prototype: O) -> &mut Self {
+        self.inherit = Some(prototype.into());
         self
     }
 
@@ -1652,8 +1648,8 @@ impl<'context> ConstructorBuilder<'context> {
     ///
     /// Default is `Function.prototype`
     #[inline]
-    pub fn custom_prototype(&mut self, prototype: JsValue) -> &mut Self {
-        self.custom_prototype = Some(prototype);
+    pub fn custom_prototype<O: Into<JsPrototype>>(&mut self, prototype: O) -> &mut Self {
+        self.custom_prototype = Some(prototype.into());
         self
     }
 
@@ -1688,15 +1684,14 @@ impl<'context> ConstructorBuilder<'context> {
             constructor.insert("length", length);
             constructor.insert("name", name);
 
-            if let Some(proto) = &self.custom_prototype {
-                constructor.set_prototype_instance(proto.clone());
+            if let Some(proto) = self.custom_prototype.take() {
+                constructor.set_prototype(proto);
             } else {
-                constructor.set_prototype_instance(
+                constructor.set_prototype(
                     self.context
                         .standard_objects()
                         .function_object()
-                        .prototype()
-                        .into(),
+                        .prototype(),
                 );
             }
             constructor.insert_property(
@@ -1721,15 +1716,10 @@ impl<'context> ConstructorBuilder<'context> {
             );
 
             if let Some(proto) = self.inherit.take() {
-                prototype.set_prototype_instance(proto);
+                prototype.set_prototype(proto);
             } else {
-                prototype.set_prototype_instance(
-                    self.context
-                        .standard_objects()
-                        .object_object()
-                        .prototype()
-                        .into(),
-                );
+                prototype
+                    .set_prototype(self.context.standard_objects().object_object().prototype());
             }
         }
 
diff --git a/boa/src/value/display.rs b/boa/src/value/display.rs
index 0497a9c908..3f8a671131 100644
--- a/boa/src/value/display.rs
+++ b/boa/src/value/display.rs
@@ -31,18 +31,18 @@ macro_rules! print_obj_value {
     (internals of $obj:expr, $display_fn:ident, $indent:expr, $encounters:expr) => {
         {
             let object = $obj.borrow();
-            if object.prototype_instance().is_object() {
+            if let Some(object) = object.prototype() {
                 vec![format!(
                     "{:>width$}: {}",
                     "__proto__",
-                    $display_fn(object.prototype_instance(), $encounters, $indent.wrapping_add(4), true),
+                    $display_fn(&object.clone().into(), $encounters, $indent.wrapping_add(4), true),
                     width = $indent,
                 )]
             } else {
                 vec![format!(
                     "{:>width$}: {}",
                     "__proto__",
-                    object.prototype_instance().display(),
+                    JsValue::Null.display(),
                     width = $indent,
                 )]
             }
diff --git a/boa/src/value/mod.rs b/boa/src/value/mod.rs
index 0426820172..7b3dfe327a 100644
--- a/boa/src/value/mod.rs
+++ b/boa/src/value/mod.rs
@@ -290,7 +290,11 @@ impl JsValue {
                     return property;
                 }
 
-                object.borrow().prototype_instance().get_property(key)
+                object
+                    .prototype()
+                    .as_ref()
+                    .map_or(JsValue::Null, |obj| obj.clone().into())
+                    .get_property(key)
             }
             _ => None,
         }