diff --git a/.env.example b/.env.example
index 582a421..58542ef 100644
--- a/.env.example
+++ b/.env.example
@@ -40,6 +40,8 @@ OUTPUT=
 TEMPDIR=
 # Put temporary image web server domain
 TMP_DOMAIN=
+# Threshold where optional space saving methods will be performed
+THRESHOLD=
 # Port for serving metrics. Metrics served are compatible with Prometheus.
 METRICS=