diff --git a/include/nuttx/syslog/syslog.h b/include/nuttx/syslog/syslog.h
index c43bb8cfb4e..efe009059b8 100644
--- a/include/nuttx/syslog/syslog.h
+++ b/include/nuttx/syslog/syslog.h
@@ -43,6 +43,7 @@
 
 #include <nuttx/config.h>
 #include <nuttx/compiler.h>
+#include <stdarg.h>
 
 /****************************************************************************
  * Pre-processor Definitions