Index: kernel/generic/include/cpu.h
===================================================================
--- kernel/generic/include/cpu.h	(revision 06f81c443fbc7ab0126fd4a61a5c82ae88c9c582)
+++ kernel/generic/include/cpu.h	(revision 24be331ea10d154caa5f9eead16febf3485cbcf7)
@@ -98,7 +98,8 @@
 
 #ifdef CONFIG_FPU_LAZY
+	/* For synchronization between FPU trap and thread destructor. */
 	IRQ_SPINLOCK_DECLARE(fpu_lock);
-	struct thread *fpu_owner;
 #endif
+	_Atomic(struct thread *) fpu_owner;
 
 	/**