diff --git a/libImaging/Draw.c b/libImaging/Draw.c
index 1241c8d3b..c29132112 100644
--- a/libImaging/Draw.c
+++ b/libImaging/Draw.c
@@ -49,6 +49,13 @@
 #define BLEND(mask, in1, in2, tmp1, tmp2)\
         (MULDIV255(in1, 255 - mask, tmp1) + MULDIV255(in2, mask, tmp2))
 
+/*
+ * Rounds around zero (up=torwards zero, down=away from zero)
+ * This guarantees that ROUND_UP|DOWN(f) == -ROUND_UP|DOWN(-f)
+ */
+#define ROUND_UP(f)    ((int) ((f) >= 0.0 ? floor((f) + 0.5F) : -floor(fabs(f) + 0.5F)))
+#define ROUND_DOWN(f)    ((int) ((f) >= 0.0 ? ceil((f) - 0.5F) : -ceil(fabs(f) - 0.5F)))
+
 /* -------------------------------------------------------------------- */
 /* Primitives                                                           */
 /* -------------------------------------------------------------------- */