diff --git a/app/controllers/citations_controller.rb b/app/controllers/citations_controller.rb
index dd121d4c..024a602e 100644
--- a/app/controllers/citations_controller.rb
+++ b/app/controllers/citations_controller.rb
@@ -165,7 +165,7 @@ def destroy
 
   def send_citation(citation)
     if citation.pdf.persisted?
-      redirect_to url_for(citation.pdf), allow_other_hosts: true
+      redirect_to(url_for(citation.pdf), allow_other_host: true)
     else
       head 400
     end