diff --git a/core/src/avm2/globals.rs b/core/src/avm2/globals.rs
index 932a0bf89..80d13b9cd 100644
--- a/core/src/avm2/globals.rs
+++ b/core/src/avm2/globals.rs
@@ -682,6 +682,13 @@ pub fn load_player_globals<'gc>(
         domain,
         script,
     )?;
+    class(
+        activation,
+        flash::display::jointstyle::create_class(mc),
+        implicit_deriver,
+        domain,
+        script,
+    )?;
 
     // package `flash.geom`
     activation
diff --git a/core/src/avm2/globals/flash/display.rs b/core/src/avm2/globals/flash/display.rs
index 3b9f6454d..2d3ffea6a 100644
--- a/core/src/avm2/globals/flash/display.rs
+++ b/core/src/avm2/globals/flash/display.rs
@@ -5,6 +5,7 @@ pub mod displayobjectcontainer;
 pub mod framelabel;
 pub mod graphics;
 pub mod interactiveobject;
+pub mod jointstyle;
 pub mod movieclip;
 pub mod scene;
 pub mod shape;
diff --git a/core/src/avm2/globals/flash/display/jointstyle.rs b/core/src/avm2/globals/flash/display/jointstyle.rs
new file mode 100644
index 000000000..4f02f1876
--- /dev/null
+++ b/core/src/avm2/globals/flash/display/jointstyle.rs
@@ -0,0 +1,66 @@
+//! `flash.display.JointStyle` builtin/prototype
+
+use crate::avm2::activation::Activation;
+use crate::avm2::class::{Class, ClassAttributes};
+use crate::avm2::method::Method;
+use crate::avm2::names::{Namespace, QName};
+use crate::avm2::object::Object;
+use crate::avm2::traits::Trait;
+use crate::avm2::value::Value;
+use crate::avm2::Error;
+use gc_arena::{GcCell, MutationContext};
+
+/// Implements `flash.display.JointStyle`'s instance constructor.
+pub fn instance_init<'gc>(
+    activation: &mut Activation<'_, 'gc, '_>,
+    this: Option<Object<'gc>>,
+    _args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error> {
+    if let Some(this) = this {
+        activation.super_init(this, &[])?;
+    }
+
+    Ok(Value::Undefined)
+}
+
+/// Implements `flash.display.JointStyle`'s class constructor.
+pub fn class_init<'gc>(
+    _activation: &mut Activation<'_, 'gc, '_>,
+    _this: Option<Object<'gc>>,
+    _args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error> {
+    Ok(Value::Undefined)
+}
+
+/// Construct `JointStyle`'s class.
+pub fn create_class<'gc>(mc: MutationContext<'gc, '_>) -> GcCell<'gc, Class<'gc>> {
+    let class = Class::new(
+        QName::new(Namespace::package("flash.display"), "JointStyle"),
+        Some(QName::new(Namespace::public(), "Object").into()),
+        Method::from_builtin(instance_init),
+        Method::from_builtin(class_init),
+        mc,
+    );
+
+    let mut write = class.write(mc);
+
+    write.set_attributes(ClassAttributes::SEALED);
+
+    write.define_class_trait(Trait::from_const(
+        QName::new(Namespace::public(), "BEVEL"),
+        QName::new(Namespace::public(), "String").into(),
+        Some("bevel".into()),
+    ));
+    write.define_class_trait(Trait::from_const(
+        QName::new(Namespace::public(), "MITER"),
+        QName::new(Namespace::public(), "String").into(),
+        Some("miter".into()),
+    ));
+    write.define_class_trait(Trait::from_const(
+        QName::new(Namespace::public(), "ROUND"),
+        QName::new(Namespace::public(), "String").into(),
+        Some("round".into()),
+    ));
+
+    class
+}