diff --git a/.prettierignore b/.prettierignore
index 73ffbbf..d1d9f98 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -1,3 +1,4 @@
+.nyc_output/
 coverage/
 mdast-util-to-hast.js
 mdast-util-to-hast.min.js