diff --git a/core/src/avm2/globals/flash/display/display_object.rs b/core/src/avm2/globals/flash/display/display_object.rs
index ca70d41b1da7..d62581d1b974 100644
--- a/core/src/avm2/globals/flash/display/display_object.rs
+++ b/core/src/avm2/globals/flash/display/display_object.rs
@@ -37,7 +37,7 @@ pub fn initialize_for_allocator<'gc>(
 ) -> Object<'gc> {
     let obj = StageObject::for_display_object(context.gc(), dobj, class);
     dobj.set_placed_by_avm2_script(true);
-    dobj.set_object2(context, obj);
+    dobj.set_object2(context.gc(), obj);
 
     // [NA] Should these run for everything?
     dobj.post_instantiation(context, None, Instantiator::Avm2, false);
@@ -51,6 +51,14 @@ pub fn initialize_for_allocator<'gc>(
     dobj.base().set_skip_next_enter_frame(true);
     dobj.on_construction_complete(context);
 
+    // All MovieClips constructed from ActionScript start out as orphans. If,
+    // at the end of a frame, this MovieClip is no longer an orphan, it will
+    // automatically be removed from the orphan list by
+    // `OrphanManager::cleanup_dead_orphans`.
+    if let Some(movie_clip) = dobj.as_movie_clip() {
+        context.orphan_manager.add_orphan_obj(movie_clip.into());
+    }
+
     obj.into()
 }
 
diff --git a/core/src/avm2/globals/flash/display/simple_button.rs b/core/src/avm2/globals/flash/display/simple_button.rs
index 5e5cc363aff3..51c8a8297ac3 100644
--- a/core/src/avm2/globals/flash/display/simple_button.rs
+++ b/core/src/avm2/globals/flash/display/simple_button.rs
@@ -34,7 +34,7 @@ pub fn simple_button_allocator<'gc>(
             button.post_instantiation(activation.context, None, Instantiator::Avm2, false);
             let display_object = button.into();
             let obj = StageObject::for_display_object(activation.gc(), display_object, orig_class);
-            display_object.set_object2(activation.context, obj);
+            display_object.set_object2(activation.gc(), obj);
             return Ok(obj.into());
         }
 
diff --git a/core/src/display_object.rs b/core/src/display_object.rs
index 3ed5ac9b7710..67063741f035 100644
--- a/core/src/display_object.rs
+++ b/core/src/display_object.rs
@@ -1852,14 +1852,14 @@ pub trait TDisplayObject<'gc>:
     /// Retrieve the parent of this display object.
     ///
     /// This version of the function implements the concept of parenthood as
-    /// seen in AVM1. Notably, it disallows access to the `Stage` and to
-    /// non-AVM1 DisplayObjects; for an unfiltered concept of parent,
-    /// use the `parent` method.
+    /// seen in AVM1. Notably, it disallows access to the `Stage` and to a
+    /// `LoaderDisplay`; for an unfiltered concept of parent, use the `parent`
+    /// method.
     #[no_dynamic]
     fn avm1_parent(self) -> Option<DisplayObject<'gc>> {
         self.parent()
             .filter(|p| p.as_stage().is_none())
-            .filter(|p| !p.movie().is_action_script_3())
+            .filter(|p| p.as_loader_display().is_none())
     }
 
     /// Retrieve the parent of this display object.
@@ -2229,6 +2229,7 @@ pub trait TDisplayObject<'gc>:
     fn set_has_explicit_name(self, value: bool) {
         self.base().set_has_explicit_name(value);
     }
+
     fn state(&self) -> Option<ButtonState> {
         None
     }
@@ -2251,6 +2252,20 @@ pub trait TDisplayObject<'gc>:
     ///    as properties on the class
     fn construct_frame(self, _context: &mut UpdateContext<'gc>) {}
 
+    /// Whether this DisplayObject is an AVM2 orphan object. Objects that are
+    /// no longer AVM2 orphans (e.g. they have been adopted) will be
+    /// automatically removed from the global orphan list by
+    /// `OrphanManager::cleanup_dead_orphans`.
+    ///
+    /// There are two ways a DisplayObject can become an AVM2 orphan:
+    /// 1 - The clip has no parent
+    /// 2 - The clip has a parent, but the parent is from an AVM1 movie
+    #[no_dynamic]
+    fn is_avm2_orphan(self) -> bool {
+        self.parent()
+            .is_none_or(|p| !p.movie().is_action_script_3())
+    }
+
     /// To be called when an AVM2 display object has finished being constructed.
     ///
     /// This function must be called once and ONLY once, after the object's
@@ -2532,7 +2547,7 @@ pub trait TDisplayObject<'gc>:
 
     fn object2(self) -> Option<Avm2StageObject<'gc>>;
 
-    fn set_object2(self, _context: &mut UpdateContext<'gc>, _to: Avm2StageObject<'gc>) {}
+    fn set_object2(self, _mc: &Mutation<'gc>, _to: Avm2StageObject<'gc>) {}
 
     #[no_dynamic]
     fn object2_or_null(self) -> Avm2Value<'gc> {
@@ -2850,6 +2865,7 @@ impl<'gc> DisplayObject<'gc> {
         pub fn as_morph_shape for MorphShape;
         pub fn as_video for Video;
         pub fn as_bitmap for Bitmap;
+        pub fn as_loader_display for LoaderDisplay;
     }
 
     pub fn as_interactive(self) -> Option<InteractiveObject<'gc>> {
diff --git a/core/src/display_object/avm2_button.rs b/core/src/display_object/avm2_button.rs
index 30ecc76f353c..7d9e8032f53f 100644
--- a/core/src/display_object/avm2_button.rs
+++ b/core/src/display_object/avm2_button.rs
@@ -658,8 +658,8 @@ impl<'gc> TDisplayObject<'gc> for Avm2Button<'gc> {
         self.0.object.get()
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        let write = Gc::write(context.gc(), self.0);
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
+        let write = Gc::write(mc, self.0);
         unlock!(write, Avm2ButtonData, object).set(Some(to));
     }
 
diff --git a/core/src/display_object/bitmap.rs b/core/src/display_object/bitmap.rs
index cafde0eefe10..9b92d7ec6b20 100644
--- a/core/src/display_object/bitmap.rs
+++ b/core/src/display_object/bitmap.rs
@@ -391,8 +391,8 @@ impl<'gc> TDisplayObject<'gc> for Bitmap<'gc> {
         self.0.avm2_object.get()
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        self.set_avm2_object(context.gc(), Some(to));
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
+        self.set_avm2_object(mc, Some(to));
     }
 
     fn movie(self) -> Arc<SwfMovie> {
diff --git a/core/src/display_object/edit_text.rs b/core/src/display_object/edit_text.rs
index 91a557506a1a..5805ef6661d0 100644
--- a/core/src/display_object/edit_text.rs
+++ b/core/src/display_object/edit_text.rs
@@ -2574,8 +2574,8 @@ impl<'gc> TDisplayObject<'gc> for EditText<'gc> {
         self.0.object.get().and_then(|o| o.as_avm2_object())
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        self.set_object(Some(to.into()), context.gc());
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
+        self.set_object(Some(to.into()), mc);
     }
 
     fn self_bounds(self) -> Rectangle<Twips> {
diff --git a/core/src/display_object/graphic.rs b/core/src/display_object/graphic.rs
index be263fbbbb2b..b8a49aecd0bc 100644
--- a/core/src/display_object/graphic.rs
+++ b/core/src/display_object/graphic.rs
@@ -158,7 +158,7 @@ impl<'gc> TDisplayObject<'gc> for Graphic<'gc> {
                 self.into(),
                 class_object,
             ) {
-                Ok(object) => self.set_object2(activation.context, object),
+                Ok(object) => self.set_object2(activation.gc(), object),
                 Err(e) => {
                     tracing::error!("Got error when constructing AVM2 side of shape: {}", e)
                 }
@@ -249,8 +249,7 @@ impl<'gc> TDisplayObject<'gc> for Graphic<'gc> {
         self.0.avm2_object.get()
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        let mc = context.gc();
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
         unlock!(Gc::write(mc, self.0), GraphicData, avm2_object).set(Some(to));
     }
 
diff --git a/core/src/display_object/loader_display.rs b/core/src/display_object/loader_display.rs
index 2d2c14bfc72a..c503865e0855 100644
--- a/core/src/display_object/loader_display.rs
+++ b/core/src/display_object/loader_display.rs
@@ -94,8 +94,7 @@ impl<'gc> TDisplayObject<'gc> for LoaderDisplay<'gc> {
         self.0.avm2_object.get()
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        let mc = context.gc();
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
         unlock!(Gc::write(mc, self.0), LoaderDisplayData, avm2_object).set(Some(to))
     }
 
diff --git a/core/src/display_object/morph_shape.rs b/core/src/display_object/morph_shape.rs
index c0322efecc46..1dedc7d6939b 100644
--- a/core/src/display_object/morph_shape.rs
+++ b/core/src/display_object/morph_shape.rs
@@ -90,8 +90,7 @@ impl<'gc> TDisplayObject<'gc> for MorphShape<'gc> {
         self.0.object.get()
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        let mc = context.gc();
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
         unlock!(Gc::write(mc, self.0), MorphShapeData, object).set(Some(to))
     }
 
@@ -103,7 +102,7 @@ impl<'gc> TDisplayObject<'gc> for MorphShape<'gc> {
             // We don't need to call the initializer method, as AVM2 can't link
             // a custom class to a MorphShape, and the initializer method for
             // MorphShape itself is a no-op
-            self.set_object2(context, object);
+            self.set_object2(context.gc(), object);
 
             self.on_construction_complete(context);
         }
diff --git a/core/src/display_object/movie_clip.rs b/core/src/display_object/movie_clip.rs
index afdf5edab426..6fa800ae7acb 100644
--- a/core/src/display_object/movie_clip.rs
+++ b/core/src/display_object/movie_clip.rs
@@ -187,8 +187,6 @@ pub struct MovieClipData<'gc> {
     attached_audio: Lock<Option<NetStream<'gc>>>,
 
     /// The next MovieClip in the AVM1 execution list.
-    ///
-    /// `None` in an AVM2 movie.
     next_avm1_clip: Lock<Option<MovieClip<'gc>>>,
 
     audio_stream: Cell<Option<SoundInstanceHandle>>,
@@ -421,8 +419,8 @@ impl<'gc> MovieClip<'gc> {
 
     /// Execute all other timeline actions on this object.
     pub fn run_frame_avm1(self, context: &mut UpdateContext<'gc>) {
-        if !self.movie().is_action_script_3() {
-            // Run my load/enterFrame clip event.
+        // Run my load/enterFrame clip event.
+        if !self.movie().is_action_script_3() || !context.root_swf.is_action_script_3() {
             let is_load_frame = !self.0.contains_flag(MovieClipFlags::INITIALIZED);
             if is_load_frame {
                 self.event_dispatch(context, ClipEvent::Load);
@@ -1995,7 +1993,11 @@ impl<'gc> MovieClip<'gc> {
         let object =
             Avm2StageObject::for_display_object(context.gc(), display_object, class_object);
 
-        self.set_object2(context, object);
+        self.set_object2(context.gc(), object);
+
+        if self.is_avm2_orphan() {
+            context.orphan_manager.add_orphan_obj(self.into());
+        }
     }
 
     /// Construct the AVM2 side of this object.
@@ -2032,7 +2034,10 @@ impl<'gc> MovieClip<'gc> {
         let class_object = context.avm2.classes().avm1movie;
         let object = Avm2StageObject::for_display_object(context.gc(), self.into(), class_object);
 
-        self.set_object2(context, object);
+        self.set_object2(context.gc(), object);
+
+        // No need to mark `self` as an orphan, as it's about to be adopted by
+        // the AVM2 `Loader` object
     }
 
     pub fn register_frame_script(
@@ -2602,7 +2607,7 @@ impl<'gc> TDisplayObject<'gc> for MovieClip<'gc> {
 
         self.set_default_instance_name(context);
 
-        if !self.movie().is_action_script_3() {
+        if !self.movie().is_action_script_3() || !context.root_swf.is_action_script_3() {
             context.avm1.add_to_exec_list(context.gc(), self);
 
             self.construct_as_avm1_object(context, init_object, instantiated_by, run_frame);
@@ -2617,12 +2622,9 @@ impl<'gc> TDisplayObject<'gc> for MovieClip<'gc> {
         self.0.object2.get()
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        let write = Gc::write(context.gc(), self.0);
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
+        let write = Gc::write(mc, self.0);
         unlock!(write, MovieClipData, object2).set(Some(to));
-        if self.parent().is_none() {
-            context.orphan_manager.add_orphan_obj(self.into());
-        }
     }
 
     fn set_perspective_projection(self, mut perspective_projection: Option<PerspectiveProjection>) {
diff --git a/core/src/display_object/text.rs b/core/src/display_object/text.rs
index 7f51f0646b01..352afe442651 100644
--- a/core/src/display_object/text.rs
+++ b/core/src/display_object/text.rs
@@ -267,7 +267,7 @@ impl<'gc> TDisplayObject<'gc> for Text<'gc> {
             // We don't need to call the initializer method, as AVM2 can't link
             // a custom class to a StaticText, and the initializer method for
             // StaticText itself is a no-op
-            self.set_object2(context, object);
+            self.set_object2(context.gc(), object);
 
             self.on_construction_complete(context);
         }
@@ -281,8 +281,7 @@ impl<'gc> TDisplayObject<'gc> for Text<'gc> {
         self.0.avm2_object.get()
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        let mc = context.gc();
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
         unlock!(Gc::write(mc, self.0), TextData, avm2_object).set(Some(to));
     }
 }
diff --git a/core/src/display_object/video.rs b/core/src/display_object/video.rs
index d5b1e953655b..3ec42c45b073 100644
--- a/core/src/display_object/video.rs
+++ b/core/src/display_object/video.rs
@@ -179,8 +179,7 @@ impl<'gc> Video<'gc> {
         ))
     }
 
-    fn set_object(&self, context: &mut UpdateContext<'gc>, to: AvmObject<'gc>) {
-        let mc = context.gc();
+    fn set_object(&self, mc: &Mutation<'gc>, to: AvmObject<'gc>) {
         unlock!(Gc::write(mc, self.0), VideoData, object).set(Some(to));
     }
 
@@ -432,7 +431,7 @@ impl<'gc> TDisplayObject<'gc> for Video<'gc> {
                 Some(context.avm1.prototypes(self.swf_version()).video),
                 Avm1NativeObject::Video(self),
             );
-            self.set_object(context, object.into());
+            self.set_object(context.gc(), object.into());
         }
 
         self.seek(context, starting_seek);
@@ -448,7 +447,7 @@ impl<'gc> TDisplayObject<'gc> for Video<'gc> {
             // itself only sets the size of the Video- the Video already has the
             // correct size at this point.
 
-            self.set_object2(context, object);
+            self.set_object2(context.gc(), object);
 
             self.on_construction_complete(context);
         }
@@ -552,8 +551,8 @@ impl<'gc> TDisplayObject<'gc> for Video<'gc> {
         self.0.object.get().and_then(|o| o.as_avm2_object())
     }
 
-    fn set_object2(self, context: &mut UpdateContext<'gc>, to: Avm2StageObject<'gc>) {
-        self.set_object(context, to.into());
+    fn set_object2(self, mc: &Mutation<'gc>, to: Avm2StageObject<'gc>) {
+        self.set_object(mc, to.into());
     }
 
     fn avm1_text_field_bindings(&self) -> Option<Ref<'_, [Avm1TextFieldBinding<'gc>]>> {
diff --git a/core/src/frame_lifecycle.rs b/core/src/frame_lifecycle.rs
index a53f7b16c924..1563bad3bebb 100644
--- a/core/src/frame_lifecycle.rs
+++ b/core/src/frame_lifecycle.rs
@@ -72,32 +72,41 @@ pub enum FramePhase {
 pub fn run_all_phases_avm2(context: &mut UpdateContext<'_>) {
     let stage = context.stage;
 
-    if !stage.movie().is_action_script_3() {
-        return;
-    }
+    // We may still have AVM2 orphans that we need to run frames for even though
+    // the root movie is AVM1. However, we don't run any stage phases if the
+    // root movie is AVM1.
+    let is_root_movie_as3 = stage.movie().is_action_script_3();
 
     *context.frame_phase = FramePhase::Enter;
     OrphanManager::each_orphan_obj(context, |orphan, context| {
         orphan.enter_frame(context);
     });
-    stage.enter_frame(context);
+    if is_root_movie_as3 {
+        stage.enter_frame(context);
+    }
 
     *context.frame_phase = FramePhase::Construct;
     OrphanManager::each_orphan_obj(context, |orphan, context| {
         orphan.construct_frame(context);
     });
-    stage.construct_frame(context);
-    stage.frame_constructed(context);
+    if is_root_movie_as3 {
+        stage.construct_frame(context);
+        stage.frame_constructed(context);
+    }
 
     *context.frame_phase = FramePhase::FrameScripts;
     OrphanManager::each_orphan_obj(context, |orphan, context| {
         orphan.run_frame_scripts(context);
     });
-    stage.run_frame_scripts(context);
+    if is_root_movie_as3 {
+        stage.run_frame_scripts(context);
+    }
     MovieClip::run_frame_script_cleanup(context);
 
     *context.frame_phase = FramePhase::Exit;
-    stage.exit_frame(context);
+    if is_root_movie_as3 {
+        stage.exit_frame(context);
+    }
 
     // We cannot easily remove dead `GcWeak` instances from the orphan list
     // inside `each_orphan_movie`, since the callback may modify the orphan list.
diff --git a/core/src/orphan_manager.rs b/core/src/orphan_manager.rs
index 181879037ec1..8c8eac7b4cd9 100644
--- a/core/src/orphan_manager.rs
+++ b/core/src/orphan_manager.rs
@@ -65,6 +65,10 @@ impl<'gc> OrphanManager<'gc> {
     pub fn cleanup_dead_orphans(&mut self, mc: &Mutation<'gc>) {
         self.orphans_mut().retain(|d| {
             if let Some(dobj) = valid_orphan(*d, mc) {
+                let has_avm1_parent = dobj
+                    .parent()
+                    .is_some_and(|p| !p.movie().is_action_script_3());
+
                 // All clips that become orphaned (have their parent removed, or start out with no parent)
                 // get added to the orphan list. However, there's a distinction between clips
                 // that are removed from a RemoveObject tag, and clips that are removed from ActionScript.
@@ -78,14 +82,18 @@ impl<'gc> OrphanManager<'gc> {
                 // indefinitely (if there are no remaining strong references, they will eventually
                 // be garbage collected).
                 //
-                // To detect this, we check 'placed_by_avm2_script'. This flag get set to 'true'
+                // To detect this, we check 'placed_by_script'. This flag get set to 'true'
                 // for objects constructed from ActionScript, and for objects moved around
                 // in the timeline (add/remove child, swap depths) by ActionScript. A
                 // RemoveObject tag will only affect objects instantiated by the timeline,
                 // which have not been moved in the displaylist by ActionScript. Therefore,
-                // any orphan we see that has 'placed_by_avm2_script()' should stay on the orphan
+                // any orphan we see that has 'placed_by_script()' should stay on the orphan
                 // list, because it was not removed by a RemoveObject tag.
-                dobj.placed_by_avm2_script()
+                //
+                // Also, we consider AVM2 MovieClips loaded into an AVM1 parent to always
+                // be orphans, since we know they were placed by AVM1 code and not by
+                // the timeline.
+                dobj.placed_by_avm2_script() || has_avm1_parent
             } else {
                 false
             }
@@ -109,7 +117,7 @@ fn valid_orphan<'gc>(
     mc: &Mutation<'gc>,
 ) -> Option<DisplayObject<'gc>> {
     if let Some(dobj) = dobj.upgrade(mc) {
-        if dobj.parent().is_none() {
+        if dobj.is_avm2_orphan() {
             return Some(dobj);
         }
     }
diff --git a/tests/tests/swfs/avm1/mixed_avm/avm2.swf b/tests/tests/swfs/avm1/mixed_avm/avm2.swf
new file mode 100644
index 000000000000..2e79cdcb3414
Binary files /dev/null and b/tests/tests/swfs/avm1/mixed_avm/avm2.swf differ
diff --git a/tests/tests/swfs/avm1/mixed_avm/output.txt b/tests/tests/swfs/avm1/mixed_avm/output.txt
new file mode 100644
index 000000000000..769224495587
--- /dev/null
+++ b/tests/tests/swfs/avm1/mixed_avm/output.txt
@@ -0,0 +1,5 @@
+_level0.target
+undefined
+_level0.target.abc
+_level0.target.abc
+_level0.target.abc
diff --git a/tests/tests/swfs/avm1/mixed_avm/test.swf b/tests/tests/swfs/avm1/mixed_avm/test.swf
new file mode 100644
index 000000000000..3b777e03edbb
Binary files /dev/null and b/tests/tests/swfs/avm1/mixed_avm/test.swf differ
diff --git a/tests/tests/swfs/avm1/mixed_avm/test.toml b/tests/tests/swfs/avm1/mixed_avm/test.toml
new file mode 100644
index 000000000000..1e15fdf27598
--- /dev/null
+++ b/tests/tests/swfs/avm1/mixed_avm/test.toml
@@ -0,0 +1 @@
+num_frames = 5