diff --git a/lib/roken/roken-common.h b/lib/roken/roken-common.h
index 480f94cd1..465f81d2d 100644
--- a/lib/roken/roken-common.h
+++ b/lib/roken/roken-common.h
@@ -69,6 +69,10 @@
 #define min(a,b) (((a)<(b))?(a):(b))
 #endif
 
+#ifndef abs
+#define abs(x) (((x) < 0) ? (-x) : (x))
+#endif
+
 #ifndef TRUE
 #define TRUE 1
 #endif