diff --git a/prune.go b/prune.go
index 30b3314..ed8b3e6 100644
--- a/prune.go
+++ b/prune.go
@@ -80,6 +80,7 @@ var DefaultDirectories = []string{
 
 // DefaultExtensions pruned.
 var DefaultExtensions = []string{
+	".markdown",
 	".md",
 	".ts",
 	".jst",