diff --git a/include/strings.h b/include/strings.h
index db0960b4..b7a5ea08 100644
--- a/include/strings.h
+++ b/include/strings.h
@@ -5,6 +5,7 @@
 extern "C" {
 #endif
 
+#include <features.h>
 
 #define __NEED_size_t
 #define __NEED_locale_t