diff --git a/src/lib-sieve/plugins/vacation/cmd-vacation.c b/src/lib-sieve/plugins/vacation/cmd-vacation.c
index f4e5706283b8c71d0c43369abe06ec249b751de0..5d057fef9a837e6cf904bd8de3ba10b328be04c4 100644
--- a/src/lib-sieve/plugins/vacation/cmd-vacation.c
+++ b/src/lib-sieve/plugins/vacation/cmd-vacation.c
@@ -659,7 +659,10 @@ static int ext_vacation_operation_execute
 		
 				array_append(&norm_addresses, &addr_norm, 1);			
 			} else {
-				/* FIXME: report proper warning */
+				sieve_runtime_error(renv, NULL,
+					"specified :addresses item '%s' is invalid: %s for vacation action "
+					"(ignored)",
+					str_sanitize(str_c(raw_address),128), error);
 			}
 		}