diff --git a/camlibs/stv0680/demosaic_sharpen.c b/camlibs/stv0680/demosaic_sharpen.c
index f273b98bf..91415e0f0 100644
--- a/camlibs/stv0680/demosaic_sharpen.c
+++ b/camlibs/stv0680/demosaic_sharpen.c
@@ -67,6 +67,7 @@
  * 
  */
 
+#include <stdlib.h>
 #include "demosaic_sharpen.h"
 
 /* we define bayer as