diff --git a/lib/hdb/hdb.c b/lib/hdb/hdb.c
index 80b69e33e..b2304c56f 100644
--- a/lib/hdb/hdb.c
+++ b/lib/hdb/hdb.c
@@ -174,9 +174,14 @@ hdb_check_db_format(krb5_context context, HDB *db)
     unsigned ver;
     int foo;
 
+    ret = db->hdb_lock(context, db, HDB_RLOCK);
+    if (ret)
+	return ret;
+
     tag.data = HDB_DB_FORMAT_ENTRY;
     tag.length = strlen(tag.data);
     ret = (*db->hdb__get)(context, db, tag, &version);
+    db->hdb_unlock(context, db);
     if(ret)
 	return ret;
     foo = sscanf(version.data, "%u", &ver);
@@ -200,12 +205,19 @@ hdb_init_db(krb5_context context, HDB *db)
     if(ret != HDB_ERR_NOENTRY)
 	return ret;
     
+    ret = db->hdb_lock(context, db, HDB_WLOCK);
+    if (ret)
+	return ret;
+
     tag.data = HDB_DB_FORMAT_ENTRY;
     tag.length = strlen(tag.data);
     snprintf(ver, sizeof(ver), "%u", HDB_DB_FORMAT);
     version.data = ver;
     version.length = strlen(version.data) + 1; /* zero terminated */
     ret = (*db->hdb__put)(context, db, 0, tag, version);
+    ret = db->hdb_unlock(context, db);
+    if (ret)
+	return ret;
     return ret;
 }