diff --git a/install_roundcube.sh b/install_roundcube.sh
index a7bb81a..0fc7cd1 100755
--- a/install_roundcube.sh
+++ b/install_roundcube.sh
@@ -296,8 +296,14 @@ DEFAULT_APACHE_VHOST_DIR="/usr/local/apache2/conf/vhosts"
 DEFAULT_DB_HOST="localhost"
 DEFAULT_DB_NAME="roundcubemail"
 DEFAULT_DB_USER="roundcube"
-DEFAULT_DEBIAN_MYSQL_CREDENTIALS="--defaults-file=/etc/mysql/debian.cnf"
-DEFAULT_MYSQL_CREDENTIALS="--defaults-file=/usr/local/mysql/sys-maint.cnf"
+if [[ -f "/usr/local/mysql/sys-maint.cnf" ]] ; then
+   DEFAULT_MYSQL_CREDENTIALS="--defaults-file=/usr/local/mysql/sys-maint.cnf"
+elif [[ -f "/etc/mysql/debian.cnf" ]] ; then
+   DEFAULT_MYSQL_CREDENTIALS="--defaults-file=/etc/mysql/debian.cnf"
+else
+   DEFAULT_MYSQL_CREDENTIALS=""
+fi
+DEFAULT_DEBIAN_MYSQL_CREDENTIALS="/etc/mysql/debian.cnf"
 
 [[ -n "$ROUNDCUBE_VERSION" ]] || fatal "Roundcube Version (ROUNDCUBE_VERSION) not present!"
 [[ -n "$WEBSITE_NAME" ]] || fatal "Website's name (WEBSITE_NAME) not present!"