diff --git a/.prettierignore b/.prettierignore
index dc8d24746..22b998da8 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -19,6 +19,7 @@ components/*
 dist/*
 libtextsecure/libsignal-protocol.js
 test/fixtures.js
+libtextsecure/test/blanket_mocha.js
 test/blanket_mocha.js
 
 /**/*.json