diff --git a/src/notifications.scm b/src/notifications.scm
index 349f28c..d2ffa7c 100644
--- a/src/notifications.scm
+++ b/src/notifications.scm
@@ -121,7 +121,7 @@
     `((to . ,(brmember-info mr 'mail))
       (subject . "Připomínka členských příspěvků / Membership fees reminder")
       (body . ,(reminder-email-body mr))
-      (header .,(list (format "Content-Type: text/plain; charset=\"UTF-8\"")))
+      (headers . ,(list "Content-Type: text/plain; charset=\"UTF-8\""))
       )))
 
  ;; Creates and prints reminder email for given member record