--- src/dimacsparser.h.orig	2016-01-05 09:44:15 UTC
+++ src/dimacsparser.h
@@ -25,6 +25,7 @@ THE SOFTWARE.
 #define DIMACSPARSER_H
 
 #include <string>
+#include <cstdlib>
 #include "streambuffer.h"
 #include "cryptominisat4/cryptominisat.h"
 
