Include <stdio.h> for declarations of printf and putchar, to avoid a
build failure with future compilers which do not support implicit
function declarations.

diff --git a/src/libmawk/makescan.c b/src/libmawk/makescan.c
index 5ca9eb28d50646fe..519ff2972cb8f3e4 100644
--- a/src/libmawk/makescan.c
+++ b/src/libmawk/makescan.c
@@ -23,6 +23,8 @@ the GNU General Public License, version 2, 1991.
 #include  "scan.h"
 #include  "mawk.h"
 
+#include <stdio.h>
+
 void mawk_scan_init(mawk_state_t * MAWK)
 {
 	register char *p;