diff --git a/Libraries/LibJS/Bytecode/Builtins.h b/Libraries/LibJS/Bytecode/Builtins.h
index b7ea0a63451..31c478ba10d 100644
--- a/Libraries/LibJS/Bytecode/Builtins.h
+++ b/Libraries/LibJS/Bytecode/Builtins.h
@@ -23,7 +23,8 @@ namespace JS::Bytecode {
     O(MathRandom, math_random, Math, random, 0) \
     O(MathRound, math_round, Math, round, 1)    \
     O(MathSqrt, math_sqrt, Math, sqrt, 1)       \
-    O(MathSin, math_sin, Math, sin, 1)
+    O(MathSin, math_sin, Math, sin, 1)          \
+    O(MathCos, math_cos, Math, cos, 1)
 
 enum class Builtin : u8 {
 #define DEFINE_BUILTIN_ENUM(name, ...) name,
diff --git a/Libraries/LibJS/Bytecode/Interpreter.cpp b/Libraries/LibJS/Bytecode/Interpreter.cpp
index 542a8fef729..f6dc83c79d3 100644
--- a/Libraries/LibJS/Bytecode/Interpreter.cpp
+++ b/Libraries/LibJS/Bytecode/Interpreter.cpp
@@ -2821,6 +2821,8 @@ static ThrowCompletionOr<Value> dispatch_builtin_call(Bytecode::Interpreter& int
         return TRY(MathObject::sqrt_impl(interpreter.vm(), interpreter.get(arguments[0])));
     case Builtin::MathSin:
         return TRY(MathObject::sin_impl(interpreter.vm(), interpreter.get(arguments[0])));
+    case Builtin::MathCos:
+        return TRY(MathObject::cos_impl(interpreter.vm(), interpreter.get(arguments[0])));
     case Bytecode::Builtin::__Count:
         VERIFY_NOT_REACHED();
     }
diff --git a/Libraries/LibJS/Runtime/MathObject.cpp b/Libraries/LibJS/Runtime/MathObject.cpp
index 9a0e5214ea3..8460dfbc5cc 100644
--- a/Libraries/LibJS/Runtime/MathObject.cpp
+++ b/Libraries/LibJS/Runtime/MathObject.cpp
@@ -43,7 +43,7 @@ void MathObject::initialize(Realm& realm)
     define_native_function(realm, vm.names.min, min, 2, attr);
     define_native_function(realm, vm.names.trunc, trunc, 1, attr);
     define_native_function(realm, vm.names.sin, sin, 1, attr, Bytecode::Builtin::MathSin);
-    define_native_function(realm, vm.names.cos, cos, 1, attr);
+    define_native_function(realm, vm.names.cos, cos, 1, attr, Bytecode::Builtin::MathCos);
     define_native_function(realm, vm.names.tan, tan, 1, attr);
     define_native_function(realm, vm.names.pow, pow, 2, attr, Bytecode::Builtin::MathPow);
     define_native_function(realm, vm.names.exp, exp, 1, attr, Bytecode::Builtin::MathExp);
@@ -392,10 +392,10 @@ JS_DEFINE_NATIVE_FUNCTION(MathObject::clz32)
 }
 
 // 21.3.2.12 Math.cos ( x ), https://tc39.es/ecma262/#sec-math.cos
-JS_DEFINE_NATIVE_FUNCTION(MathObject::cos)
+ThrowCompletionOr<Value> MathObject::cos_impl(VM& vm, Value value)
 {
     // 1. Let n be ? ToNumber(x).
-    auto number = TRY(vm.argument(0).to_number(vm));
+    auto number = TRY(value.to_number(vm));
 
     // 2. If n is NaN, n is +∞𝔽, or n is -∞𝔽, return NaN.
     if (number.is_nan() || number.is_infinity())
@@ -409,6 +409,11 @@ JS_DEFINE_NATIVE_FUNCTION(MathObject::cos)
     return Value(::cos(number.as_double()));
 }
 
+JS_DEFINE_NATIVE_FUNCTION(MathObject::cos)
+{
+    return cos_impl(vm, vm.argument(0));
+}
+
 // 21.3.2.13 Math.cosh ( x ), https://tc39.es/ecma262/#sec-math.cosh
 JS_DEFINE_NATIVE_FUNCTION(MathObject::cosh)
 {
diff --git a/Libraries/LibJS/Runtime/MathObject.h b/Libraries/LibJS/Runtime/MathObject.h
index 73f371f7c3d..847b0e106da 100644
--- a/Libraries/LibJS/Runtime/MathObject.h
+++ b/Libraries/LibJS/Runtime/MathObject.h
@@ -29,6 +29,7 @@ public:
     static ThrowCompletionOr<Value> sum_precise_impl(VM&, Value);
     static ThrowCompletionOr<Value> imul_impl(VM&, Value, Value);
     static ThrowCompletionOr<Value> sin_impl(VM&, Value);
+    static ThrowCompletionOr<Value> cos_impl(VM&, Value);
 
     static Value random_impl();