diff --git a/drivers/syslog/syslog_intbuffer.c b/drivers/syslog/syslog_intbuffer.c
index 6347e179f0179..cdff96df3a043 100644
--- a/drivers/syslog/syslog_intbuffer.c
+++ b/drivers/syslog/syslog_intbuffer.c
@@ -249,6 +249,7 @@ int syslog_add_intbuffer(int ch)
 int syslog_flush_intbuffer(bool force)
 {
   syslog_putc_t putfunc;
+  irqstate_t flags;
   int ch;
   int i;
 
@@ -256,7 +257,7 @@ int syslog_flush_intbuffer(bool force)
    * concurrent modification by other tasks.
    */
 
-  sched_lock();
+  flags = enter_critical_section();
 
   do
     {
@@ -293,7 +294,7 @@ int syslog_flush_intbuffer(bool force)
     }
   while (ch != EOF);
 
-  sched_unlock();
+  leave_critical_section(flags);
 
   return ch;
 }
diff --git a/sched/misc/assert.c b/sched/misc/assert.c
index 0079014782765..343a042f76952 100644
--- a/sched/misc/assert.c
+++ b/sched/misc/assert.c
@@ -536,8 +536,6 @@ void _assert(FAR const char *filename, int linenum,
 
   flags = enter_critical_section();
 
-  sched_lock();
-
   /* try to save current context if regs is null */
 
   if (regs == NULL)
@@ -672,7 +670,5 @@ void _assert(FAR const char *filename, int linenum,
 #endif
     }
 
-  sched_unlock();
-
   leave_critical_section(flags);
 }