diff --git a/Kernel/VM/MemoryManager.cpp b/Kernel/VM/MemoryManager.cpp
index fca0b8589a..f1c0c32591 100644
--- a/Kernel/VM/MemoryManager.cpp
+++ b/Kernel/VM/MemoryManager.cpp
@@ -87,6 +87,7 @@ MemoryManager::~MemoryManager()
 
 void MemoryManager::protect_kernel_image()
 {
+    ScopedSpinLock page_lock(kernel_page_directory().get_lock());
     // Disable writing to the kernel text and rodata segments.
     for (size_t i = (FlatPtr)&start_of_kernel_text; i < (FlatPtr)&start_of_kernel_data; i += PAGE_SIZE) {
         auto& pte = *ensure_pte(kernel_page_directory(), VirtualAddress(i));
@@ -193,10 +194,11 @@ void MemoryManager::parse_memory_map()
     ASSERT(m_user_physical_pages > 0);
 }
 
-PageTableEntry* MemoryManager::pte(const PageDirectory& page_directory, VirtualAddress vaddr)
+PageTableEntry* MemoryManager::pte(PageDirectory& page_directory, VirtualAddress vaddr)
 {
     ASSERT_INTERRUPTS_DISABLED();
     ASSERT(s_mm_lock.own_lock());
+    ASSERT(page_directory.get_lock().own_lock());
     u32 page_directory_table_index = (vaddr.get() >> 30) & 0x3;
     u32 page_directory_index = (vaddr.get() >> 21) & 0x1ff;
     u32 page_table_index = (vaddr.get() >> 12) & 0x1ff;
@@ -213,6 +215,7 @@ PageTableEntry* MemoryManager::ensure_pte(PageDirectory& page_directory, Virtual
 {
     ASSERT_INTERRUPTS_DISABLED();
     ASSERT(s_mm_lock.own_lock());
+    ASSERT(page_directory.get_lock().own_lock());
     u32 page_directory_table_index = (vaddr.get() >> 30) & 0x3;
     u32 page_directory_index = (vaddr.get() >> 21) & 0x1ff;
     u32 page_table_index = (vaddr.get() >> 12) & 0x1ff;
@@ -259,6 +262,7 @@ void MemoryManager::release_pte(PageDirectory& page_directory, VirtualAddress va
 {
     ASSERT_INTERRUPTS_DISABLED();
     ASSERT(s_mm_lock.own_lock());
+    ASSERT(page_directory.get_lock().own_lock());
     u32 page_directory_table_index = (vaddr.get() >> 30) & 0x3;
     u32 page_directory_index = (vaddr.get() >> 21) & 0x1ff;
     u32 page_table_index = (vaddr.get() >> 12) & 0x1ff;
diff --git a/Kernel/VM/MemoryManager.h b/Kernel/VM/MemoryManager.h
index 24c6fedf70..3d62a05f43 100644
--- a/Kernel/VM/MemoryManager.h
+++ b/Kernel/VM/MemoryManager.h
@@ -191,7 +191,7 @@ private:
     PageDirectoryEntry* quickmap_pd(PageDirectory&, size_t pdpt_index);
     PageTableEntry* quickmap_pt(PhysicalAddress);
 
-    PageTableEntry* pte(const PageDirectory&, VirtualAddress);
+    PageTableEntry* pte(PageDirectory&, VirtualAddress);
     PageTableEntry* ensure_pte(PageDirectory&, VirtualAddress);
     void release_pte(PageDirectory&, VirtualAddress, bool);
 
diff --git a/Kernel/VM/PageDirectory.h b/Kernel/VM/PageDirectory.h
index 98c256b920..880524cc78 100644
--- a/Kernel/VM/PageDirectory.h
+++ b/Kernel/VM/PageDirectory.h
@@ -57,6 +57,8 @@ public:
     Process* process() { return m_process; }
     const Process* process() const { return m_process; }
 
+    RecursiveSpinLock& get_lock() { return m_lock; }
+
 private:
     PageDirectory(Process&, const RangeAllocator* parent_range_allocator);
     PageDirectory();
@@ -67,6 +69,7 @@ private:
     RefPtr<PhysicalPage> m_directory_table;
     RefPtr<PhysicalPage> m_directory_pages[4];
     HashMap<u32, RefPtr<PhysicalPage>> m_page_tables;
+    RecursiveSpinLock m_lock;
 };
 
 }
diff --git a/Kernel/VM/Region.cpp b/Kernel/VM/Region.cpp
index a1d39daf24..9552264eb1 100644
--- a/Kernel/VM/Region.cpp
+++ b/Kernel/VM/Region.cpp
@@ -229,6 +229,7 @@ Bitmap& Region::ensure_cow_map() const
 
 bool Region::map_individual_page_impl(size_t page_index)
 {
+    ASSERT(m_page_directory->get_lock().own_lock());
     auto page_vaddr = vaddr_from_page_index(page_index);
     auto* pte = MM.ensure_pte(*m_page_directory, page_vaddr);
     if (!pte) {
@@ -260,8 +261,9 @@ bool Region::map_individual_page_impl(size_t page_index)
 
 bool Region::remap_page(size_t page_index, bool with_flush)
 {
-    ASSERT(m_page_directory);
     ScopedSpinLock lock(s_mm_lock);
+    ASSERT(m_page_directory);
+    ScopedSpinLock page_lock(m_page_directory->get_lock());
     ASSERT(physical_page(page_index));
     bool success = map_individual_page_impl(page_index);
     if (with_flush)
@@ -273,6 +275,7 @@ void Region::unmap(ShouldDeallocateVirtualMemoryRange deallocate_range)
 {
     ScopedSpinLock lock(s_mm_lock);
     ASSERT(m_page_directory);
+    ScopedSpinLock page_lock(m_page_directory->get_lock());
     size_t count = page_count();
     for (size_t i = 0; i < count; ++i) {
         auto vaddr = vaddr_from_page_index(i);
@@ -302,6 +305,7 @@ void Region::set_page_directory(PageDirectory& page_directory)
 bool Region::map(PageDirectory& page_directory)
 {
     ScopedSpinLock lock(s_mm_lock);
+    ScopedSpinLock page_lock(page_directory.get_lock());
     set_page_directory(page_directory);
 #ifdef MM_DEBUG
     dbg() << "MM: Region::map() will map VMO pages " << first_page_index() << " - " << last_page_index() << " (VMO page count: " << vmobject().page_count() << ")";