diff --git a/Userland/Libraries/LibWeb/Animations/AnimationEffect.h b/Userland/Libraries/LibWeb/Animations/AnimationEffect.h
index 2dec4af9d0..56204443aa 100644
--- a/Userland/Libraries/LibWeb/Animations/AnimationEffect.h
+++ b/Userland/Libraries/LibWeb/Animations/AnimationEffect.h
@@ -141,6 +141,8 @@ public:
     Optional<double> current_iteration() const;
     Optional<double> transformed_progress() const;
 
+    HashTable<CSS::PropertyID> const& target_properties() const { return m_target_properties; }
+
     virtual DOM::Element* target() const { return {}; }
     virtual bool is_keyframe_effect() const { return false; }
 
@@ -183,6 +185,10 @@ protected:
     // Used for calculating transitions in StyleComputer
     Phase m_previous_phase { Phase::Idle };
     double m_previous_current_iteration { 0.0 };
+
+    // https://www.w3.org/TR/web-animations-1/#target-property
+    // Note: Only modified by child classes
+    HashTable<CSS::PropertyID> m_target_properties;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp b/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp
index 3a776a857d..d18a0ffc97 100644
--- a/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp
+++ b/Userland/Libraries/LibWeb/Animations/KeyframeEffect.cpp
@@ -817,7 +817,7 @@ WebIDL::ExceptionOr<void> KeyframeEffect::set_keyframes(Optional<JS::Handle<JS::
     compute_missing_keyframe_offsets(m_keyframes);
 
     auto keyframe_set = adopt_ref(*new KeyFrameSet);
-    HashTable<CSS::PropertyID> animated_properties;
+    m_target_properties.clear();
 
     for (auto& keyframe : m_keyframes) {
         Animations::KeyframeEffect::KeyFrameSet::ResolvedKeyFrame resolved_keyframe;
@@ -825,14 +825,14 @@ WebIDL::ExceptionOr<void> KeyframeEffect::set_keyframes(Optional<JS::Handle<JS::
         auto key = static_cast<u64>(keyframe.computed_offset.value() * 100 * AnimationKeyFrameKeyScaleFactor);
 
         for (auto const& [property_id, property_value] : keyframe.parsed_properties()) {
-            animated_properties.set(property_id);
+            m_target_properties.set(property_id);
             resolved_keyframe.resolved_properties.set(property_id, property_value);
         }
 
         keyframe_set->keyframes_by_key.insert(key, resolved_keyframe);
     }
 
-    generate_initial_and_final_frames(keyframe_set, animated_properties);
+    generate_initial_and_final_frames(keyframe_set, m_target_properties);
     m_key_frame_set = keyframe_set;
 
     return {};