--- a/adpcm/decode.c
+++ b/adpcm/decode.c
@@ -6,6 +6,7 @@
  * Usage : decode [-3|4|5] [-a|u|l] < infile > outfile
  */
 #include <stdio.h>
+#include <stdlib.h>
 #include "g72x.h"
 
 
--- a/adpcm/encode.c
+++ b/adpcm/encode.c
@@ -6,6 +6,7 @@
  * Usage : encode [-3|4|5] [-a|u|l] < infile > outfile
  */
 #include <stdio.h>
+#include <stdlib.h>
 #include "g72x.h"