diff --git a/src/lib-sieve/ext-envelope.c b/src/lib-sieve/ext-envelope.c
index 5d26cbfbdc3520fe32039a9573ec8f403abcc58c..76e914cf6b01424555cdfc49f620da0445a56a24 100644
--- a/src/lib-sieve/ext-envelope.c
+++ b/src/lib-sieve/ext-envelope.c
@@ -188,7 +188,7 @@ static int ext_envelope_get_fields
 		value = msgdata->return_path;
 	else if ( strncmp(field, "to", 2) == 0 )
 		value = msgdata->to_address;	
-	else if ( strncmp(field, "to", 2) == 0 )	
+	else if ( strncmp(field, "auth", 2) == 0 ) /* Non-standard */
 		value = msgdata->auth_user;
 		
 	if ( value != NULL )