diff --git a/src/compat/convert.c b/src/compat/convert.c
index 2c033c1..6ad213b 100644
--- a/src/compat/convert.c
+++ b/src/compat/convert.c
@@ -145,7 +145,7 @@ convert( config_t *box )
 			fputs( "dbcreate failed\n", stderr );
 			goto err2;
 		}
-		if (db->open( db, 0, iumname, 0, DB_HASH, 0, 0 )) {
+		if ((db->open)( db, 0, iumname, 0, DB_HASH, 0, 0 )) {
 			fputs( "cannot open db\n", stderr );
 			db->close( db, 0 );
 			goto err2;
diff --git a/src/drv_maildir.c b/src/drv_maildir.c
index c365a0c..d8779f5 100644
--- a/src/drv_maildir.c
+++ b/src/drv_maildir.c
@@ -521,7 +521,7 @@ maildir_scan( maildir_store_t *ctx, msglist_t *msglist )
 				fputs( "Maildir error: db_create() failed\n", stderr );
 				return DRV_BOX_BAD;
 			}
-			if (tdb->open( tdb, 0, 0, 0, DB_HASH, DB_CREATE, 0 )) {
+			if ((tdb->open)( tdb, 0, 0, 0, DB_HASH, DB_CREATE, 0 )) {
 				fputs( "Maildir error: tdb->open() failed\n", stderr );
 				tdb->close( tdb, 0 );
 				return DRV_BOX_BAD;
@@ -825,7 +825,7 @@ maildir_select( store_t *gctx, int minuid, int maxuid, int *excs, int nexcs,
 			fputs( "Maildir error: db_create() failed\n", stderr );
 			goto bork;
 		}
-		if ((ret = ctx->db->open( ctx->db, 0, uvpath, 0, DB_HASH, DB_CREATE, 0 ))) {
+		if ((ret = (ctx->db->open)( ctx->db, 0, uvpath, 0, DB_HASH, DB_CREATE, 0 ))) {
 			ctx->db->err( ctx->db, ret, "Maildir error: db->open(%s)", uvpath );
 		  dbork:
 			ctx->db->close( ctx->db, 0 );
diff --git a/src/mdconvert.c b/src/mdconvert.c
index 9d8e623..a6b2ea3 100644
--- a/src/mdconvert.c
+++ b/src/mdconvert.c
@@ -96,7 +96,7 @@ convert( const char *box, int altmap )
 		fputs( "Error: db_create() failed\n", stderr );
 		goto tbork;
 	}
-	if ((ret = db->open( db, 0, dbpath, 0, DB_HASH, DB_CREATE, 0 ))) {
+	if ((ret = (db->open)( db, 0, dbpath, 0, DB_HASH, DB_CREATE, 0 ))) {
 		db->err( db, ret, "Error: db->open(%s)", dbpath );
 	  dbork:
 		db->close( db, 0 );