Index: kernel/test/mm/mapping1.c
===================================================================
--- kernel/test/mm/mapping1.c	(revision 96b02eb9b2f96f3843b8275c254c43a9cb6c8c88)
+++ kernel/test/mm/mapping1.c	(revision f66b565b8b2a1484baa2cb20482e3e642c37a723)
@@ -35,4 +35,5 @@
 #include <typedefs.h>
 #include <debug.h>
+#include <arch.h>
 
 #define PAGE0  0x10000000
@@ -58,4 +59,6 @@
 	*((uint32_t *) frame1) = VALUE1;
 	
+	page_table_lock(AS, true);
+
 	TPRINTF("Mapping virtual address %p to physical address %p.\n",
 	    (void *) PAGE0, (void *) KA2PA(frame0));
@@ -65,4 +68,6 @@
 	    (void *) PAGE1, (void *) KA2PA(frame1));
 	page_mapping_insert(AS_KERNEL, PAGE1, KA2PA(frame1), PAGE_PRESENT | PAGE_WRITE);
+
+	page_table_unlock(AS, true);
 	
 	v0 = *((uint32_t *) PAGE0);