diff --git a/pkg/alertmanager/alertmanager.go b/pkg/alertmanager/alertmanager.go
index 1cdc3a80df3..44e9664116e 100644
--- a/pkg/alertmanager/alertmanager.go
+++ b/pkg/alertmanager/alertmanager.go
@@ -395,7 +395,7 @@ func (am *Alertmanager) ApplyConfig(userID string, conf *config.Config, rawCfg s
 		return notifier
 	})
 	if err != nil {
-		return nil
+		return err
 	}
 
 	timeIntervals := make(map[string][]timeinterval.TimeInterval, len(conf.MuteTimeIntervals)+len(conf.TimeIntervals))