diff --git a/Tests/LibWeb/Text/expected/WebAnimations/misc/keyframe-effect-cloning.txt b/Tests/LibWeb/Text/expected/WebAnimations/misc/keyframe-effect-cloning.txt
new file mode 100644
index 00000000000..09a341626ea
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/WebAnimations/misc/keyframe-effect-cloning.txt
@@ -0,0 +1,2 @@
+anim count: 1
+keyframe: {"offset":null,"computedOffset":1,"easing":"linear","composite":"auto","marginLeft":"10px"}
diff --git a/Tests/LibWeb/Text/input/WebAnimations/misc/keyframe-effect-cloning.html b/Tests/LibWeb/Text/input/WebAnimations/misc/keyframe-effect-cloning.html
new file mode 100644
index 00000000000..dea3a17ee25
--- /dev/null
+++ b/Tests/LibWeb/Text/input/WebAnimations/misc/keyframe-effect-cloning.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<script src="../../include.js"></script>
+<script>
+    test(() => {
+        let effect = new KeyframeEffect(null, [{ marginLeft: "10px" }]);
+        let copiedEffect = new KeyframeEffect(effect);
+        let copiedKeyframes = copiedEffect.getKeyframes();
+        println(`anim count: ${copiedKeyframes.length}`);
+        if (copiedKeyframes.length > 0)
+            println(`keyframe: ${JSON.stringify(copiedKeyframes[0])}`);
+    })
+</script>
diff --git a/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp b/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp
index 822a2778deb..7bf2dc92561 100644
--- a/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp
+++ b/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp
@@ -706,8 +706,8 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyframeEffect>> KeyframeEffect::construct_
     //   - effect target,
     effect->m_target_element = source->target();
 
-    // FIXME:
     //   - keyframes,
+    effect->m_keyframes = source->m_keyframes;
 
     //   - composite operation, and
     effect->set_composite(source->composite());
