diff --git a/lib/linguist/vendor.yml b/lib/linguist/vendor.yml
index ecd2bf4c..a77fa417 100644
--- a/lib/linguist/vendor.yml
+++ b/lib/linguist/vendor.yml
@@ -201,6 +201,6 @@
 - Mercury/
 
 # R packages
-- vignettes/
-- inst/extdata/
+- ^vignettes/
+- ^inst/extdata/