diff --git a/sched/init/nx_start.c b/sched/init/nx_start.c
index 6361695fbf..ee98a3db70 100644
--- a/sched/init/nx_start.c
+++ b/sched/init/nx_start.c
@@ -759,6 +759,13 @@ void nx_start(void)
 
   syslog_initialize();
 
+  /* Disables context switching beacuse we need take the memory manager
+   * semaphore on this CPU so that it will not be available on the other
+   * CPUs until we have finished initialization.
+   */
+
+  sched_lock();
+
 #ifdef CONFIG_SMP
   /* Start all CPUs *********************************************************/
 
@@ -782,6 +789,10 @@ void nx_start(void)
 
   DEBUGVERIFY(nx_bringup());
 
+  /* Let other threads have access to the memory manager */
+
+  sched_unlock();
+
   /* The IDLE Loop **********************************************************/
 
   /* When control is return to this point, the system is idle. */