diff --git a/.env.example b/.env.example
index b54a44a..ad4741d 100644
--- a/.env.example
+++ b/.env.example
@@ -4,4 +4,8 @@ TESLACAM_DIRECTORY=/mnt/TeslaCam
 # Local dev server only (ignored when run under a WSGI server like gunicorn)
 FLASK_RUN_HOST=0.0.0.0
 FLASK_RUN_PORT=5000
-FLASK_DEBUG=0
\ No newline at end of file
+FLASK_DEBUG=0
+
+# Seconds to cache the TeslaCam directory scan (default 300). Hit /refresh to
+# force a re-scan.
+SCAN_CACHE_TTL=3600
\ No newline at end of file