diff --git a/extras/post-install.sh b/extras/post-install.sh
index c222ce9cb39677a295a939a38e6915244b3b897f..2b5e74680ce71de5a5bc9812c15c431f08ce5693 100644
--- a/extras/post-install.sh
+++ b/extras/post-install.sh
@@ -144,7 +144,8 @@ CREATE TABLE GBInfo (
 ) ENGINE = MYISAM;
 CREATE TABLE Link (
   mrnaAcc char(20) NOT NULL,
-  protAcc char(20) NOT NULL,
+  protAcc char(20) DEFAULT NULL,
+  created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
   PRIMARY KEY (mrnaAcc),
   UNIQUE KEY protAcc (protAcc)
 ) ENGINE = MYISAM;