diff --git a/README.md b/README.md
index 2441047..839ed5a 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,7 @@ Flarum is the next-generation forum software that makes online discussion fun. I
 | -------- | ----------- | ---- | ------------- |
 | **GID** | Flarum user id | *optional* | 991
 | **UID** | Flarum group id | *optional* | 991
+| **DEBUG** | Flarum debug mode | *optional* | false
 | **FORUM_URL** | Forum URL | **required** | none
 | **DB_HOST** | MariaDB instance ip/hostname | *optional* | mariadb
 | **DB_USER** | MariaDB database username | *optional* | flarum
diff --git a/startup b/startup
index 22fd3ca..5823384 100644
--- a/startup
+++ b/startup
@@ -4,11 +4,13 @@
 export DB_HOST
 export DB_USER
 export DB_NAME
+export DEBUG
 
 # Default values
 DB_HOST=${DB_HOST:-mariadb}
 DB_USER=${DB_USER:-flarum}
 DB_NAME=${DB_NAME:-flarum}
+DEBUG=${DEBUG:-false}
 
 # Required env variables
 if [ -z "$DB_PASS" ]; then
@@ -105,6 +107,11 @@ else
 
 fi
 
+# Set flarum debug mode
+if [ -f "config.php" ]; then
+  sed -i "s|\('debug' =>\) .*|\1 ${DEBUG},|" config.php
+fi
+
 # Removing installation files
 rm -f config.sql config.yml