diff --git a/vignettes/regtools.Rmd b/vignettes/regtools.Rmd
index 73c6d11..5b84b77 100644
--- a/vignettes/regtools.Rmd
+++ b/vignettes/regtools.Rmd
@@ -10,7 +10,7 @@ output: rmarkdown::html_vignette
 
 # regtools 
 
-## Novel tools tools for linear, nonlinear and nonparametric regression.
+## Novel tools for linear, nonlinear and nonparametric regression.
 
 These tools are associated with my forthcoming book, <i>From Linear
 Models to Machine Learning: Modern Statistical Regression and