diff --git a/conf/.env.example b/conf/.env.example
index 7a89b8c..d1cd9be 100644
--- a/conf/.env.example
+++ b/conf/.env.example
@@ -6,6 +6,10 @@
 # NOTE: If any of your values contain a space or a hash you will need to
 # wrap the entire value in quotes. (eg. MAIL_FROM_NAME="BookStack Mailer")
 
+# Application environment
+# Can be 'production', 'development', 'testing' or 'demo'
+APP_ENV=production
+
 # Enable debug mode
 # Shows advanced debug information and errors.
 # CAN EXPOSE OTHER VARIABLES, LEAVE DISABLED
@@ -82,5 +86,3 @@ STORAGE_TYPE=local
 # Can be 'list' or 'grid'
 APP_VIEWS_BOOKS=list
 APP_VIEWS_BOOKSHELVES=grid
-
-