diff --git a/servers/slapd/back-bdb/ctxcsn.c b/servers/slapd/back-bdb/ctxcsn.c
index 14c83edc0e..7c2b31ec36 100644
--- a/servers/slapd/back-bdb/ctxcsn.c
+++ b/servers/slapd/back-bdb/ctxcsn.c
@@ -50,6 +50,8 @@ bdb_csn_commit(
 	size_t			textlen = sizeof textbuf;
 	EntryInfo		*eip = NULL;
 
+	assert( !BER_BVISNULL( &op->o_bd->be_context_csn ) );
+
 	if ( ei ) {
 		e = ei->bei_e;
 	}