diff --git a/Libraries/LibJS/Runtime/IndexedProperties.cpp b/Libraries/LibJS/Runtime/IndexedProperties.cpp
index 91f2830c398..f630de2cf43 100644
--- a/Libraries/LibJS/Runtime/IndexedProperties.cpp
+++ b/Libraries/LibJS/Runtime/IndexedProperties.cpp
@@ -50,18 +50,29 @@ void SimpleIndexedPropertyStorage::put(u32 index, Value value, PropertyAttribute
     if (index >= m_array_size) {
         m_array_size = index + 1;
         grow_storage_if_needed();
+    } else {
+        if (m_packed_elements[index].is_special_empty_value()) {
+            --m_number_of_empty_elements;
+        }
     }
     m_packed_elements[index] = value;
+    if (value.is_special_empty_value()) {
+        ++m_number_of_empty_elements;
+    }
 }
 
 void SimpleIndexedPropertyStorage::remove(u32 index)
 {
     VERIFY(index < m_array_size);
+    ++m_number_of_empty_elements;
     m_packed_elements[index] = js_special_empty_value();
 }
 
 ValueAndAttributes SimpleIndexedPropertyStorage::take_first()
 {
+    if (m_packed_elements.first().is_special_empty_value()) {
+        --m_number_of_empty_elements;
+    }
     m_array_size--;
     return { m_packed_elements.take_first(), default_attributes };
 }
@@ -70,14 +81,32 @@ ValueAndAttributes SimpleIndexedPropertyStorage::take_last()
 {
     m_array_size--;
     auto last_element = m_packed_elements[m_array_size];
+    if (last_element.is_special_empty_value()) {
+        --m_number_of_empty_elements;
+    }
     m_packed_elements[m_array_size] = js_special_empty_value();
     return { last_element, default_attributes };
 }
 
 bool SimpleIndexedPropertyStorage::set_array_like_size(size_t new_size)
 {
+    if (new_size == m_array_size)
+        return true;
+
+    auto old_size = m_array_size;
     m_array_size = new_size;
     m_packed_elements.resize_with_default_value_and_keep_capacity(new_size, js_special_empty_value());
+
+    if (old_size <= m_array_size) {
+        m_number_of_empty_elements += m_array_size - old_size;
+    } else {
+        m_number_of_empty_elements = 0;
+        for (auto& value : m_packed_elements) {
+            if (value.is_special_empty_value())
+                ++m_number_of_empty_elements;
+        }
+    }
+
     return true;
 }
 
diff --git a/Libraries/LibJS/Runtime/IndexedProperties.h b/Libraries/LibJS/Runtime/IndexedProperties.h
index 03e599f3d6a..039e66a6e9b 100644
--- a/Libraries/LibJS/Runtime/IndexedProperties.h
+++ b/Libraries/LibJS/Runtime/IndexedProperties.h
@@ -90,12 +90,15 @@ public:
         return ValueAndAttributes { m_packed_elements.data()[index], default_attributes };
     }
 
+    bool has_empty_elements() const { return m_number_of_empty_elements.value() > 0; }
+
 private:
     friend GenericIndexedPropertyStorage;
 
     void grow_storage_if_needed();
 
     size_t m_array_size { 0 };
+    Checked<size_t> m_number_of_empty_elements { 0 };
     Vector<Value> m_packed_elements;
 };