--- flex-2.6.4.ori/src/flexdef.h        2017-05-03 20:13:14.000000000 +0200
+++ flex-2.6.4/src/flexdef.h    2018-08-24 02:04:51.159854880 +0200
@@ -47,6 +47,7 @@
 #include <libgen.h> /* for XPG version of basename(3) */
 #include <string.h>
 #include <math.h>
+#include <malloc.h>
 
 #ifdef HAVE_ASSERT_H
 #include <assert.h>