diff --git a/wand/compare.c b/wand/compare.c
index 0498197..607ed6c 100644
--- a/wand/compare.c
+++ b/wand/compare.c
@@ -110,7 +110,7 @@
"-density geometry horizontal and vertical density of the image",
"-depth value image depth",
"-dissimilarity-threshold value",
- " maximum RMSE for (sub)image match",
+ " maximum distortion for (sub)image match",
"-encipher filename convert plain pixels to cipher pixels",
"-extract geometry extract area from image",
"-format \"string\" output formatted image characteristics",