diff -Nur a/libgfortran/io/close.c b/libgfortran/io/close.c
--- a/libgfortran/io/close.c	2018-10-05 15:16:21.000000000 -0500
+++ b/libgfortran/io/close.c	2019-02-22 11:21:54.547170028 -0600
@@ -28,6 +28,7 @@
 #if !HAVE_UNLINK_OPEN_FILE
 #include <string.h>
 #endif
+#include <stdlib.h>
 
 typedef enum
 { CLOSE_DELETE, CLOSE_KEEP, CLOSE_UNSPECIFIED }