1 files changed, 3 insertions, 0 deletions
diff --git a/util.h b/util.h
index f1f4f14..2a139ec 100644
--- a/util.h
+++ b/util.h
@@ -27,6 +27,9 @@
 
 #include "types.h"
 
+#ifndef ABS
+#define ABS(a)   ((a) < 0 ? -(a) : (a))
+#endif
 #ifndef MIN
 #define MIN(a,b) ((a) < (b) ? (a) : (b))
 #endif