diff --git a/Formula/pam-u2f.rb b/Formula/pam-u2f.rb
index 930355efc0b..8954ce86156 100644
--- a/Formula/pam-u2f.rb
+++ b/Formula/pam-u2f.rb
@@ -29,14 +29,15 @@ class PamU2f < Formula
     system "make", "install"
   end
 
-  def caveats; <<~EOS
-    To use a U2F key for PAM authentication, specify the full path to the
-    module (#{opt_lib}/pam/pam_u2f.so) in a PAM
-    configuration. You can find all PAM configurations in /etc/pam.d.
+  def caveats
+    <<~EOS
+      To use a U2F key for PAM authentication, specify the full path to the
+      module (#{opt_lib}/pam/pam_u2f.so) in a PAM
+      configuration. You can find all PAM configurations in /etc/pam.d.
 
-    For further installation instructions, please visit
-    https://developers.yubico.com/pam-u2f/#installation.
-  EOS
+      For further installation instructions, please visit
+      https://developers.yubico.com/pam-u2f/#installation.
+    EOS
   end
 
   test do