--- include/host_defines.h	2017-12-18 14:14:28.151154536 -0500
+++ include/host_defines.h	2017-12-18 14:17:01.927019796 -0500
@@ -47,4 +47,10 @@
  * Users Notice.
  */
 
+#include <features.h>
+
+#if __GLIBC_PREREQ(2,26)
+# define _BITS_FLOATN_H
+#endif
+
 #include "crt/host_defines.h"