diff --git a/core/src/display_object.rs b/core/src/display_object.rs
index 0904753ca3e21..00a1295ec49e1 100644
--- a/core/src/display_object.rs
+++ b/core/src/display_object.rs
@@ -1446,6 +1446,11 @@ pub trait TDisplayObject<'gc>:
 
         if let Some(ctr) = self.as_container() {
             for child in ctr.iter_render_list() {
+                // Masks clip other children without contributing visible pixels.
+                // Their animation must not move the bitmap cache's origin.
+                if (child.clip_depth() > 0 && child.allow_as_mask()) || child.maskee().is_some() {
+                    continue;
+                }
                 let matrix = *matrix * child.base().matrix();
                 bounds =
                     bounds.union(&child.render_bounds_with_transform(&matrix, true, view_matrix));
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/Test.as b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/Test.as
new file mode 100644
index 0000000000000..9c53b905a614e
--- /dev/null
+++ b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/Test.as
@@ -0,0 +1,148 @@
+package {
+    import flash.display.Bitmap;
+    import flash.display.BlendMode;
+    import flash.display.MovieClip;
+    import flash.display.Shape;
+    import flash.display.Sprite;
+    import flash.display.StageAlign;
+    import flash.display.StageScaleMode;
+    import flash.events.Event;
+    import flash.filters.ColorMatrixFilter;
+    import flash.geom.Rectangle;
+    import flash.system.fscommand;
+
+    [SWF(width="480", height="300", frameRate="30", backgroundColor="#A0A0A0")]
+    public class Test extends MovieClip {
+        [Embed(source="maskee.png")]
+        private var Maskee:Class;
+
+        private var containers:Array = [];
+        private var bitmaps:Array = [];
+        private var masks:Array = [];
+        private var frame:int = 0;
+
+        public function Test() {
+            stage.scaleMode = StageScaleMode.NO_SCALE;
+            stage.align = StageAlign.TOP_LEFT;
+
+            trace("Animated mask / filter bounds");
+            trace("Top row, left to right: ColorMatrix+HardLight, ColorMatrix, HardLight");
+            trace("Bottom row: no effects, ColorMatrix+moving clipping edge, ColorMatrix+moving bitmap");
+
+            for (var i:int = 0; i < 6; i++) {
+                var container:Sprite = new Sprite();
+                container.x = 40 + (i % 3) * 160;
+                container.y = 35 + int(i / 3) * 150;
+                addChild(container);
+
+                var bitmap:Bitmap = new Maskee();
+                bitmap.scaleX = bitmap.scaleY = 4;
+                container.addChild(bitmap);
+
+                var maskShape:Shape = new Shape();
+                container.addChild(maskShape);
+                if (i == 4) {
+                    drawMask(maskShape, 0, 0, 40, 80);
+                } else {
+                    drawMask(maskShape, -12, -12, 104, 104);
+                }
+                bitmap.mask = maskShape;
+
+                if (i == 0 || i == 1 || i == 4 || i == 5) {
+                    container.filters = [new ColorMatrixFilter([
+                        0.8, 0, 0, 0, 12,
+                        0, 0.9, 0, 0, 6,
+                        0, 0, 0.7, 0, 18,
+                        0, 0, 0, 1, 0
+                    ])];
+                }
+
+                if (i == 0 || i == 2) {
+                    container.blendMode = BlendMode.HARDLIGHT;
+                }
+
+
+                containers.push(container);
+                bitmaps.push(bitmap);
+                masks.push(maskShape);
+            }
+
+            addEventListener(Event.ENTER_FRAME, onFrame);
+        }
+
+        private function drawMask(
+            maskShape:Shape,
+            x:Number,
+            y:Number,
+            width:Number,
+            height:Number
+        ):void {
+            maskShape.graphics.clear();
+            maskShape.graphics.beginFill(0x000000);
+            maskShape.graphics.drawRect(x, y, width, height);
+            maskShape.graphics.endFill();
+        }
+
+        private function bounds(rect:Rectangle):String {
+            return rect.x.toFixed(2) + "," +
+                rect.y.toFixed(2) + "," +
+                rect.width.toFixed(2) + "," +
+                rect.height.toFixed(2);
+        }
+
+        private function onFrame(event:Event):void {
+            frame++;
+
+            var phase:int = (frame - 1) % 40;
+            var controlPhase:int = int((frame - 1) / 2) % 4;
+            var delta:Number = phase * 0.05;
+
+            for (var i:int = 0; i < 6; i++) {
+                var maskShape:Shape = masks[i];
+                var bitmap:Bitmap = bitmaps[i];
+
+                if (i == 4) {
+                    // Intentional visible clipping motion.
+                    maskShape.x = controlPhase * 10;
+                } else {
+                    // Move the mask while it still fully covers the bitmap.
+                    maskShape.x = -delta;
+                    maskShape.y = -delta;
+                }
+
+                if (i == 5) {
+                    // Intentional bitmap motion.
+                    bitmap.x = controlPhase * 2;
+                }
+            }
+
+            if (
+                frame == 1 || frame == 11 || frame == 19 ||
+                frame == 35 || frame == 40 || frame == 60 ||
+                frame == 123
+            ) {
+                trace("frame=" + frame + " delta=" + delta.toFixed(2));
+
+                for (i = 0; i < 6; i++) {
+                    trace(
+                        "case=" + i +
+                        " bitmap=" +
+                        bounds(Bitmap(bitmaps[i]).getBounds(this)) +
+                        " mask=" +
+                        bounds(Shape(masks[i]).getBounds(this)) +
+                        " container=" +
+                        bounds(Sprite(containers[i]).getBounds(this))
+                    );
+                }
+            }
+
+            if (frame == 11 || frame == 19 || frame == 35) {
+                fscommand("captureImage", "frame" + frame);
+            }
+            if (frame == 123) {
+                trace("DONE");
+                removeEventListener(Event.ENTER_FRAME, onFrame);
+            }
+        }
+    }
+}
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame11.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame11.expected.png
new file mode 100644
index 0000000000000..837c6c953fd12
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame11.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame19.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame19.expected.png
new file mode 100644
index 0000000000000..837c6c953fd12
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame19.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame35.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame35.expected.png
new file mode 100644
index 0000000000000..837c6c953fd12
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/frame35.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/maskee.png b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/maskee.png
new file mode 100644
index 0000000000000..53329c7710588
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/maskee.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/output.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/output.expected.png
new file mode 100644
index 0000000000000..837c6c953fd12
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/output.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/output.txt b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/output.txt
new file mode 100644
index 0000000000000..fc6c20bd74756
--- /dev/null
+++ b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/output.txt
@@ -0,0 +1,53 @@
+Animated mask / filter bounds
+Top row, left to right: ColorMatrix+HardLight, ColorMatrix, HardLight
+Bottom row: no effects, ColorMatrix+moving clipping edge, ColorMatrix+moving bitmap
+frame=1 delta=0.00
+case=0 bitmap=40.00,35.00,80.00,80.00 mask=28.00,23.00,104.00,104.00 container=28.00,23.00,104.00,104.00
+case=1 bitmap=200.00,35.00,80.00,80.00 mask=188.00,23.00,104.00,104.00 container=188.00,23.00,104.00,104.00
+case=2 bitmap=360.00,35.00,80.00,80.00 mask=348.00,23.00,104.00,104.00 container=348.00,23.00,104.00,104.00
+case=3 bitmap=40.00,185.00,80.00,80.00 mask=28.00,173.00,104.00,104.00 container=28.00,173.00,104.00,104.00
+case=4 bitmap=200.00,185.00,80.00,80.00 mask=200.00,185.00,40.00,80.00 container=200.00,185.00,80.00,80.00
+case=5 bitmap=360.00,185.00,80.00,80.00 mask=348.00,173.00,104.00,104.00 container=348.00,173.00,104.00,104.00
+frame=11 delta=0.50
+case=0 bitmap=40.00,35.00,80.00,80.00 mask=27.50,22.50,104.00,104.00 container=27.50,22.50,104.00,104.00
+case=1 bitmap=200.00,35.00,80.00,80.00 mask=187.50,22.50,104.00,104.00 container=187.50,22.50,104.00,104.00
+case=2 bitmap=360.00,35.00,80.00,80.00 mask=347.50,22.50,104.00,104.00 container=347.50,22.50,104.00,104.00
+case=3 bitmap=40.00,185.00,80.00,80.00 mask=27.50,172.50,104.00,104.00 container=27.50,172.50,104.00,104.00
+case=4 bitmap=200.00,185.00,80.00,80.00 mask=210.00,185.00,40.00,80.00 container=200.00,185.00,80.00,80.00
+case=5 bitmap=362.00,185.00,80.00,80.00 mask=347.50,172.50,104.00,104.00 container=347.50,172.50,104.00,104.00
+frame=19 delta=0.90
+case=0 bitmap=40.00,35.00,80.00,80.00 mask=27.10,22.10,104.00,104.00 container=27.10,22.10,104.00,104.00
+case=1 bitmap=200.00,35.00,80.00,80.00 mask=187.10,22.10,104.00,104.00 container=187.10,22.10,104.00,104.00
+case=2 bitmap=360.00,35.00,80.00,80.00 mask=347.10,22.10,104.00,104.00 container=347.10,22.10,104.00,104.00
+case=3 bitmap=40.00,185.00,80.00,80.00 mask=27.10,172.10,104.00,104.00 container=27.10,172.10,104.00,104.00
+case=4 bitmap=200.00,185.00,80.00,80.00 mask=210.00,185.00,40.00,80.00 container=200.00,185.00,80.00,80.00
+case=5 bitmap=362.00,185.00,80.00,80.00 mask=347.10,172.10,104.00,104.00 container=347.10,172.10,104.00,104.00
+frame=35 delta=1.70
+case=0 bitmap=40.00,35.00,80.00,80.00 mask=26.30,21.30,104.00,104.00 container=26.30,21.30,104.00,104.00
+case=1 bitmap=200.00,35.00,80.00,80.00 mask=186.30,21.30,104.00,104.00 container=186.30,21.30,104.00,104.00
+case=2 bitmap=360.00,35.00,80.00,80.00 mask=346.30,21.30,104.00,104.00 container=346.30,21.30,104.00,104.00
+case=3 bitmap=40.00,185.00,80.00,80.00 mask=26.30,171.30,104.00,104.00 container=26.30,171.30,104.00,104.00
+case=4 bitmap=200.00,185.00,80.00,80.00 mask=210.00,185.00,40.00,80.00 container=200.00,185.00,80.00,80.00
+case=5 bitmap=362.00,185.00,80.00,80.00 mask=346.30,171.30,104.00,104.00 container=346.30,171.30,104.00,104.00
+frame=40 delta=1.95
+case=0 bitmap=40.00,35.00,80.00,80.00 mask=26.05,21.05,104.00,104.00 container=26.05,21.05,104.00,104.00
+case=1 bitmap=200.00,35.00,80.00,80.00 mask=186.05,21.05,104.00,104.00 container=186.05,21.05,104.00,104.00
+case=2 bitmap=360.00,35.00,80.00,80.00 mask=346.05,21.05,104.00,104.00 container=346.05,21.05,104.00,104.00
+case=3 bitmap=40.00,185.00,80.00,80.00 mask=26.05,171.05,104.00,104.00 container=26.05,171.05,104.00,104.00
+case=4 bitmap=200.00,185.00,80.00,80.00 mask=230.00,185.00,40.00,80.00 container=200.00,185.00,80.00,80.00
+case=5 bitmap=366.00,185.00,80.00,80.00 mask=346.05,171.05,104.00,104.00 container=346.05,171.05,104.00,104.00
+frame=60 delta=0.95
+case=0 bitmap=40.00,35.00,80.00,80.00 mask=27.05,22.05,104.00,104.00 container=27.05,22.05,104.00,104.00
+case=1 bitmap=200.00,35.00,80.00,80.00 mask=187.05,22.05,104.00,104.00 container=187.05,22.05,104.00,104.00
+case=2 bitmap=360.00,35.00,80.00,80.00 mask=347.05,22.05,104.00,104.00 container=347.05,22.05,104.00,104.00
+case=3 bitmap=40.00,185.00,80.00,80.00 mask=27.05,172.05,104.00,104.00 container=27.05,172.05,104.00,104.00
+case=4 bitmap=200.00,185.00,80.00,80.00 mask=210.00,185.00,40.00,80.00 container=200.00,185.00,80.00,80.00
+case=5 bitmap=362.00,185.00,80.00,80.00 mask=347.05,172.05,104.00,104.00 container=347.05,172.05,104.00,104.00
+frame=123 delta=0.10
+case=0 bitmap=40.00,35.00,80.00,80.00 mask=27.90,22.90,104.00,104.00 container=27.90,22.90,104.00,104.00
+case=1 bitmap=200.00,35.00,80.00,80.00 mask=187.90,22.90,104.00,104.00 container=187.90,22.90,104.00,104.00
+case=2 bitmap=360.00,35.00,80.00,80.00 mask=347.90,22.90,104.00,104.00 container=347.90,22.90,104.00,104.00
+case=3 bitmap=40.00,185.00,80.00,80.00 mask=27.90,172.90,104.00,104.00 container=27.90,172.90,104.00,104.00
+case=4 bitmap=200.00,185.00,80.00,80.00 mask=210.00,185.00,40.00,80.00 container=200.00,185.00,80.00,80.00
+case=5 bitmap=362.00,185.00,80.00,80.00 mask=347.90,172.90,104.00,104.00 container=347.90,172.90,104.00,104.00
+DONE
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/test.swf b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/test.swf
new file mode 100644
index 0000000000000..289d6c31d0c5b
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/test.swf differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/test.toml b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/test.toml
new file mode 100644
index 0000000000000..1eeadb79075b5
--- /dev/null
+++ b/tests/tests/swfs/visual/cache_as_bitmap/animated_mask_filter_bounds/test.toml
@@ -0,0 +1,19 @@
+num_frames = 124
+
+[image_comparisons.frame11]
+trigger = "fs_command"
+tolerance = 1
+
+[image_comparisons.frame19]
+trigger = "fs_command"
+tolerance = 1
+
+[image_comparisons.frame35]
+trigger = "fs_command"
+tolerance = 1
+
+[image_comparisons.output]
+tolerance = 1
+
+[player_options]
+with_renderer = { optional = false, quality = "high" }
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/Test.as b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/Test.as
new file mode 100644
index 0000000000000..51b32c48126fe
--- /dev/null
+++ b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/Test.as
@@ -0,0 +1,47 @@
+package {
+    import flash.display.MovieClip;
+    import flash.display.StageAlign;
+    import flash.display.StageQuality;
+    import flash.display.StageScaleMode;
+    import flash.events.Event;
+    import flash.system.fscommand;
+
+    [SWF(width="160", height="160", frameRate="24", backgroundColor="#A0A0A0")]
+    public class Test extends MovieClip {
+        private var scene:MovieClip;
+        private var sampleFrame:int = 1;
+        private var holdFrames:int = 0;
+
+        public function Test() {
+            stage.scaleMode = StageScaleMode.NO_SCALE;
+            stage.align = StageAlign.TOP_LEFT;
+            stage.quality = StageQuality.HIGH;
+
+            addEventListener(Event.ENTER_FRAME, onFrame);
+        }
+
+        private function onFrame(event:Event):void {
+            if (scene == null) {
+                // The build script adds the native timeline to the root frame.
+                if (numChildren == 0) {
+                    return;
+                }
+                scene = MovieClip(getChildAt(0));
+                trace("Timeline mask cache bounds");
+            }
+            if (holdFrames > 0) {
+                holdFrames--;
+                return;
+            }
+            scene.gotoAndStop(sampleFrame);
+            holdFrames = 71;
+            trace("frame=" + scene.currentFrame);
+            fscommand("captureImage", "frame0" + sampleFrame);
+            if (sampleFrame == scene.totalFrames) {
+                removeEventListener(Event.ENTER_FRAME, onFrame);
+                trace("DONE");
+            }
+            sampleFrame++;
+        }
+    }
+}
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame01.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame01.expected.png
new file mode 100644
index 0000000000000..143db719121c7
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame01.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame02.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame02.expected.png
new file mode 100644
index 0000000000000..143db719121c7
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame02.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame03.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame03.expected.png
new file mode 100644
index 0000000000000..143db719121c7
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame03.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame04.expected.png b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame04.expected.png
new file mode 100644
index 0000000000000..143db719121c7
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/frame04.expected.png differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/output.txt b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/output.txt
new file mode 100644
index 0000000000000..e6992cea22223
--- /dev/null
+++ b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/output.txt
@@ -0,0 +1,6 @@
+Timeline mask cache bounds
+frame=1
+frame=2
+frame=3
+frame=4
+DONE
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/test.swf b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/test.swf
new file mode 100644
index 0000000000000..07265ff85fdb2
Binary files /dev/null and b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/test.swf differ
diff --git a/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/test.toml b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/test.toml
new file mode 100644
index 0000000000000..0b3931f51ea5e
--- /dev/null
+++ b/tests/tests/swfs/visual/cache_as_bitmap/timeline_mask_cache_bounds/test.toml
@@ -0,0 +1,20 @@
+num_frames = 240
+
+[player_options]
+with_renderer = { optional = false, quality = "high" }
+
+[image_comparisons.frame01]
+trigger = "fs_command"
+tolerance = 54
+
+[image_comparisons.frame02]
+trigger = "fs_command"
+tolerance = 54
+
+[image_comparisons.frame03]
+trigger = "fs_command"
+tolerance = 54
+
+[image_comparisons.frame04]
+trigger = "fs_command"
+tolerance = 54