1 files changed, 1 insertions, 0 deletions
diff --git a/defines.h b/defines.h
index c8c1350554..1f5a0054f1 100644
--- a/defines.h
+++ b/defines.h
@@ -12,6 +12,7 @@
 
 #define RUBY
 
+#include <stdlib.h>
 #ifdef __cplusplus
 # ifndef  HAVE_PROTOTYPES
 #  define HAVE_PROTOTYPES 1