diff --git a/checker/checker.go b/checker/checker.go
index a4986e941c..11dedc4c94 100644
--- a/checker/checker.go
+++ b/checker/checker.go
@@ -126,7 +126,7 @@ func (c *Checker) Init() (err error) {
 		}
 		instance.sourceDB, err = dbutil.OpenDB(*instance.sourceDBinfo)
 		if err != nil {
-			return terror.WithScope(terror.ErrTaskCheckFailedOpenDB.Generate(instance.cfg.From.User, instance.cfg.From.Host, instance.cfg.From.Port), terror.ScopeUpstream)
+			return terror.WithScope(terror.ErrTaskCheckFailedOpenDB.Delegate(err, instance.cfg.From.User, instance.cfg.From.Host, instance.cfg.From.Port), terror.ScopeUpstream)
 		}
 
 		instance.targetDBInfo = &dbutil.DBConfig{
@@ -137,7 +137,7 @@ func (c *Checker) Init() (err error) {
 		}
 		instance.targetDB, err = dbutil.OpenDB(*instance.targetDBInfo)
 		if err != nil {
-			return terror.WithScope(terror.ErrTaskCheckFailedOpenDB.Generate(instance.cfg.To.User, instance.cfg.To.Host, instance.cfg.To.Port), terror.ScopeDownstream)
+			return terror.WithScope(terror.ErrTaskCheckFailedOpenDB.Delegate(err, instance.cfg.To.User, instance.cfg.To.Host, instance.cfg.To.Port), terror.ScopeDownstream)
 		}
 
 		if _, ok := c.checkingItems[config.VersionChecking]; ok {