diff --git a/Kernel/Thread.cpp b/Kernel/Thread.cpp
index 800533429d..891a5672fe 100644
--- a/Kernel/Thread.cpp
+++ b/Kernel/Thread.cpp
@@ -46,7 +46,7 @@
 namespace Kernel {
 
 SpinLock<u8> Thread::g_tid_map_lock;
-HashMap<ThreadID, Thread*>* Thread::g_tid_map;
+READONLY_AFTER_INIT HashMap<ThreadID, Thread*>* Thread::g_tid_map;
 
 void Thread::initialize()
 {