diff --git a/lib/puppet-strings/tasks/validate.rb b/lib/puppet-strings/tasks/validate.rb
index 21251d8c..73b16bfd 100644
--- a/lib/puppet-strings/tasks/validate.rb
+++ b/lib/puppet-strings/tasks/validate.rb
@@ -34,7 +34,7 @@
       existing = File.read(filename)
 
       if generated != existing
-        warn "#{filename} is outdated"
+        warn "#{filename} is outdated; to regenerate: bundle exec rake strings:generate:reference"
         exit 1
       end
     end