diff --git a/grammar/SIPGrammar.st b/grammar/SIPGrammar.st
index ecfdfe8..90f4f59 100644
--- a/grammar/SIPGrammar.st
+++ b/grammar/SIPGrammar.st
@@ -483,7 +483,7 @@ PP.PPCompositeParser subclass: SIPGrammar [
     ]
 
     display_name [
-        ^ (self token, LWS) star / self quoted_string
+        ^ ((self token, LWS) star / self quoted_string) flatten
     ]
 
     addr_spec [