diff --git a/Kernel/VM/MemoryManager.h b/Kernel/VM/MemoryManager.h
index 52615a9e90a..b6df2b15a5a 100644
--- a/Kernel/VM/MemoryManager.h
+++ b/Kernel/VM/MemoryManager.h
@@ -105,6 +105,7 @@ extern RecursiveSpinLock s_mm_lock;
 
 class MemoryManager {
     AK_MAKE_ETERNAL
+    friend class PageDirectory;
     friend class AnonymousVMObject;
     friend class Region;
     friend class VMObject;