diff --git a/Dangerfile b/Dangerfile
index 3941cffbed3..a2cae25a6c3 100644
--- a/Dangerfile
+++ b/Dangerfile
@@ -2,8 +2,9 @@ if github.pr_json && (github.pr_json["additions"] || 0) > 250 || (github.pr_json
   warn("This pull request is big! We prefer smaller PRs whenever possible, as they are easier to review. Can this be split into a few smaller PRs?")
 end
 
-prettier_offenses = `prettier --list-different "app/assets/stylesheets/**/*.scss" "app/assets/javascripts/**/*.es6" "test/javascripts/**/*.es6"`.split('\n')
-if !prettier_offenses.empty?
+prettier_offenses = `yarn --silent prettier --list-different "app/assets/stylesheets/**/*.scss" "app/assets/javascripts/**/*.es6" "test/javascripts/**/*.es6"`.split("\n")
+
+unless prettier_offenses.empty?
   fail(%{
 This PR doesn't match our required code formatting standards, as enforced by prettier.io. <a href='https://meta.discourse.org/t/prettier-code-formatting-tool/93212'>Here's how to set up prettier in your code editor.</a>\n
 #{prettier_offenses.map { |o| github.html_link(o) }.join("\n")}