diff --git a/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp b/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp
index 634e3f457bf..3fcaf9c7cc9 100644
--- a/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp
+++ b/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp
@@ -22,9 +22,6 @@
 
 namespace JS {
 
-// NOTE: If this changes, we need to update the mmap() code to ensure correct alignment.
-static_assert(HeapBlock::block_size == 4096);
-
 BlockAllocator::~BlockAllocator()
 {
     for (auto* block : m_blocks) {
diff --git a/Userland/Libraries/LibJS/Heap/HeapBlock.cpp b/Userland/Libraries/LibJS/Heap/HeapBlock.cpp
index b1a65440790..ccbe0bbbdae 100644
--- a/Userland/Libraries/LibJS/Heap/HeapBlock.cpp
+++ b/Userland/Libraries/LibJS/Heap/HeapBlock.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2020-2024, Andreas Kling <andreas@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -18,6 +18,8 @@
 
 namespace JS {
 
+size_t HeapBlockBase::block_size = PAGE_SIZE;
+
 NonnullOwnPtr<HeapBlock> HeapBlock::create_with_cell_size(Heap& heap, CellAllocator& cell_allocator, size_t cell_size, [[maybe_unused]] char const* class_name)
 {
     char const* name = nullptr;
diff --git a/Userland/Libraries/LibJS/Heap/Internals.h b/Userland/Libraries/LibJS/Heap/Internals.h
index 08d20537d01..2bb809bb908 100644
--- a/Userland/Libraries/LibJS/Heap/Internals.h
+++ b/Userland/Libraries/LibJS/Heap/Internals.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2020-2024, Andreas Kling <andreas@ladybird.org>
  * Copyright (c) 2020-2023, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
@@ -33,7 +33,7 @@ class HeapBlockBase {
     AK_MAKE_NONCOPYABLE(HeapBlockBase);
 
 public:
-    static constexpr auto block_size = 4 * KiB;
+    static size_t block_size;
     static HeapBlockBase* from_cell(Cell const* cell)
     {
         return reinterpret_cast<HeapBlockBase*>(bit_cast<FlatPtr>(cell) & ~(HeapBlockBase::block_size - 1));