diff --git a/content/forest.md b/content/forest.md
index f77ae54..4ce00a8 100644
--- a/content/forest.md
+++ b/content/forest.md
@@ -359,6 +359,7 @@ echo 'set sendmail="/usr/bin/msmtp"' > /etc/mail.rc
   cat >~/bin/alertwrapper <<<EOF
   #!/bin/sh -e
   output="$(mktemp)"
+  trap "rm -f \"$output\"" EXIT
 
   notify () {
     { echo "Subject: $*"; echo; cat "$output"; } | msmtp lucidiot