diff --git a/cookbooks/digdag/templates/etc/promtail/digdag.yaml b/cookbooks/digdag/templates/etc/promtail/digdag.yaml
index b201922..dcdb06c 100644
--- a/cookbooks/digdag/templates/etc/promtail/digdag.yaml
+++ b/cookbooks/digdag/templates/etc/promtail/digdag.yaml
@@ -20,7 +20,7 @@ scrape_configs:
 
     pipeline_stages:
     - match:
-        selector: '{job="digdag"} !~ "^[0-9]+-[0-9]+-[0-9]+"'
+        selector: '{job="digdag"} !~ "^[0-9]{4}-[0-9]{2}-[0-9]{2}"'
         action: drop
 
     - match: