diff --git a/fluentd/files/parser/regexp.conf b/fluentd/files/parser/regexp.conf
index 14b3dbe..7df0fa6 100644
--- a/fluentd/files/parser/regexp.conf
+++ b/fluentd/files/parser/regexp.conf
@@ -1,2 +1,6 @@
     expression {{ values.format }}
+    time_key {{ values.get("time_key", "time") }}
+{%- if values.get('time_format') %}
     time_format {{ values.time_format }}
+{%- endif %}
+    keep_time_key {{ values.get("keep_time_key", False) | json }}