diff --git a/README.md b/README.md
index d65cc81..0e763dd 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,7 @@ $ docker run \
   --rm \
   --env DATABASE_TYPE: Pg \
   --env DATABASE_HOST: postgres \
+  --env DATABASE_PORT: 5432 \
   --env DATABASE_NAME: postgres \
   --env DATABASE_USER: fetchmail \
   --env DATABASE_PASSWORD: MySecretPassword \
@@ -39,6 +40,7 @@ $ docker run \
   --rm \
   --env DATABASE_TYPE: my \
   --env DATABASE_HOST: root \
+  --env DATABASE_PORT: 3306 \
   --env DATABASE_NAME: mysql \
   --env DATABASE_USER: fetchmail \
   --env DATABASE_PASSWORD: MySecretPassword \
@@ -62,6 +64,7 @@ services:
     environment:
     - DATABASE_TYPE=${DATABASE_TYPE}
     - DATABASE_HOST=${DATABASE_HOST}
+    - DATABASE_HOST=${DATABASE_PORT}
     - DATABASE_NAME=${DATABASE_NAME}
     - DATABASE_USER=${DATABASE_USER}
     - DATABASE_PASSWORD=${DATABASE_PASSWORD}
diff --git a/fetchmail.pl b/fetchmail.pl
index 18eff1f..b1c6fdd 100755
--- a/fetchmail.pl
+++ b/fetchmail.pl
@@ -15,10 +15,11 @@ use LockFile::Simple qw(lock trylock unlock);
 
 # database backend - uncomment one of these
 our $db_type=$ENV{'DATABASE_TYPE'};
-our $db_host=$ENV{'DATABASE_HOST'};
-our $db_name=$ENV{'DATABASE_NAME'};
 our $db_username=$ENV{'DATABASE_USER'};
 our $db_password=$ENV{'DATABASE_PASSWORD'};
+our $db_host=$ENV{'DATABASE_HOST'};
+our $db_port=$ENV{'DATABASE_PORT'};
+our $db_name=$ENV{'DATABASE_NAME'};
 
 # instead of changing this script, you can put your settings to /etc/mail/postfixadmin/fetchmail.conf
 # just use perl syntax there to fill the variables listed above (without the "our" keyword). Example:
@@ -60,7 +61,7 @@ if (-e $configfile) {
 }
 
 if($db_type eq "Pg" || $db_type eq "mysql") {
-  $dsn = "DBI:$db_type:database=$db_name;host=$db_host";
+  $dsn = "DBI:$db_type:database=$db_name;host=$db_host;port=$db_port";
 } else {
   log_and_die "unsupported db_type $db_type";
 }