diff --git a/servers/slapd/back-hdb/external.h b/servers/slapd/back-hdb/external.h
index 4559efd365..312e3fbb61 100644
--- a/servers/slapd/back-hdb/external.h
+++ b/servers/slapd/back-hdb/external.h
@@ -12,8 +12,7 @@
 #define BDB_HIER
 #endif
 
-#undef _BDB_EXTERNAL_H
-#undef BDB_SYMBOL
+extern BI_init	hdb_initialize;
 
 #include "../back-bdb/external.h"