diff --git a/src/lephisto.h b/src/lephisto.h
index 78f7d6a..407d2d9 100644
--- a/src/lephisto.h
+++ b/src/lephisto.h
@@ -5,7 +5,8 @@
 #define MALLOC_L(type)(malloc(sizeof(type)))
 #define CALLOC_L(type)(calloc(1, sizeof(type)))
 
-#define ABS(x)   (((x)<0)?-(x):(x))
+#define ABS(x)    (((x)<0)?-(x):(x))
+#define FABS(x)   (((x)<0.)?-(x):(x))
 
 #define MAX(x,y)  (((x)>(y))?(x):(y))
 #define MIN(x,y)  (((x)>(y))?(y):(x))