diff --git a/tests/data/slapd.conf b/tests/data/slapd.conf
index 0aa4640237..84b8a44fd6 100644
--- a/tests/data/slapd.conf
+++ b/tests/data/slapd.conf
@@ -24,6 +24,9 @@ include		@DATADIR@/test.schema
 pidfile		@TESTDIR@/slapd.1.pid
 argsfile	@TESTDIR@/slapd.1.args
 
+# allow big PDUs from anonymous (for testing purposes)
+sockbuf_max_incoming 4194303
+
 #mod#modulepath	../servers/slapd/back-@BACKEND@/
 #mod#moduleload	back_@BACKEND@.la
 #monitormod#modulepath ../servers/slapd/back-monitor/