diff --git a/libs/libc/libc.h b/libs/libc/libc.h
index 540c805595..b531fa87ff 100644
--- a/libs/libc/libc.h
+++ b/libs/libc/libc.h
@@ -25,6 +25,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <nuttx/config.h>
+
 #ifndef __ASSEMBLY__
 #  include <sys/types.h>
 #  include <stdbool.h>