diff --git a/luku19.tex b/luku19.tex
index a9581de..87c24a7 100644
--- a/luku19.tex
+++ b/luku19.tex
@@ -627,7 +627,7 @@ a complete tour will be found quickly.
 \index{heuristic}
 \index{Warnsdorff's rule}
 
-\key{Warnsdorff's rule} is a simple and good heuristic
+\key{Warnsdorff's rule} is a simple and effective heuristic
 for finding a knight's tour.
 Using the rule, it is possible to efficiently construct a tour
 even on a large board.