diff --git a/Kernel/VM/PageDirectory.cpp b/Kernel/VM/PageDirectory.cpp
index 43dbf605238..f584b6ab102 100644
--- a/Kernel/VM/PageDirectory.cpp
+++ b/Kernel/VM/PageDirectory.cpp
@@ -14,15 +14,15 @@
 
 namespace Kernel {
 
-static AK::Singleton<HashMap<u32, PageDirectory*>> s_cr3_map;
+static AK::Singleton<HashMap<FlatPtr, PageDirectory*>> s_cr3_map;
 
-static HashMap<u32, PageDirectory*>& cr3_map()
+static HashMap<FlatPtr, PageDirectory*>& cr3_map()
 {
     VERIFY_INTERRUPTS_DISABLED();
     return *s_cr3_map;
 }
 
-RefPtr<PageDirectory> PageDirectory::find_by_cr3(u32 cr3)
+RefPtr<PageDirectory> PageDirectory::find_by_cr3(FlatPtr cr3)
 {
     ScopedSpinLock lock(s_mm_lock);
     return cr3_map().get(cr3).value_or({});
diff --git a/Kernel/VM/PageDirectory.h b/Kernel/VM/PageDirectory.h
index f60348d056c..c06066cc4a9 100644
--- a/Kernel/VM/PageDirectory.h
+++ b/Kernel/VM/PageDirectory.h
@@ -28,11 +28,11 @@ public:
         return page_directory;
     }
     static NonnullRefPtr<PageDirectory> create_kernel_page_directory() { return adopt_ref(*new PageDirectory); }
-    static RefPtr<PageDirectory> find_by_cr3(u32);
+    static RefPtr<PageDirectory> find_by_cr3(FlatPtr);
 
     ~PageDirectory();
 
-    u32 cr3() const
+    FlatPtr cr3() const
     {
 #if ARCH(X86_64)
         return m_pml4t->paddr().get();