diff --git a/callagent/authorization/SIPAuthorization.st b/callagent/authorization/SIPAuthorization.st
index b40a4eb..64bcd63 100644
--- a/callagent/authorization/SIPAuthorization.st
+++ b/callagent/authorization/SIPAuthorization.st
@@ -103,6 +103,10 @@ Object subclass: SIPAuthorization [
                         url: uri.
     ]
 
+    do: aBlock [
+        (String streamContents: [:str | self nextPutAllOn: str]) do: aBlock
+    ]
+
     nextPutAllOn: aStream [
         aStream
             nextPutAll: 'Digest username="';