diff --git a/includes/CLI.php b/includes/CLI.php
index 5b0ca91..111ff06 100644
--- a/includes/CLI.php
+++ b/includes/CLI.php
@@ -121,10 +121,16 @@ public static function orders( $args, $assoc_args ) {
 	public static function customers( $args, $assoc_args ) {
 		list( $amount ) = $args;
 
+		$domain = '';
+
+		if ( ! empty( $assoc_args['email-domain'] ) ) {
+			$domain = $assoc_args['email-domain'];
+		}
+
 		static::disable_emails();
 		$progress = \WP_CLI\Utils\make_progress_bar( 'Generating customers', $amount );
 		for ( $i = 1; $i <= $amount; $i++ ) {
-			Generator\Customer::generate();
+			Generator\Customer::generate( true, $domain );
 			$progress->tick();
 		}
 		$progress->finish();
@@ -242,7 +248,21 @@ public static function coupons( $args, $assoc_args ) {
 		),
 	),
 ) );
-WP_CLI::add_command( 'wc generate customers', array( 'WC\SmoothGenerator\CLI', 'customers' ) );
+WP_CLI::add_command( 'wc generate customers', array( 'WC\SmoothGenerator\CLI', 'customers' ), array(
+	'synopsis' => array(
+		array(
+			'name'     => 'amount',
+			'type'     => 'positional',
+			'optional' => true,
+			'default'  => 100,
+		),
+		array(
+			'name'     => 'email-domain',
+			'type'     => 'assoc',
+			'optional' => true,
+		),
+	),
+) );
 
 WP_CLI::add_command( 'wc generate coupons', array( 'WC\SmoothGenerator\CLI', 'coupons' ), array(
 	'synopsis' => array(
diff --git a/includes/Generator/Customer.php b/includes/Generator/Customer.php
index 86ae7a7..f14f21d 100644
--- a/includes/Generator/Customer.php
+++ b/includes/Generator/Customer.php
@@ -15,23 +15,23 @@ class Customer extends Generator {
 	/**
 	 * Return a new customer.
 	 *
-	 * @param bool $save Save the object before returning or not.
+	 * @param bool   $save Save the object before returning or not.
+	 * @param string $emailDomain An optional domain to be used for all customers' email addresses.
 	 * @return \WC_Customer Customer object with data populated.
 	 */
-	public static function generate( $save = true ) {
+	public static function generate( $save = true, $emailDomain = '' ) {
 		self::init_faker();
 
-		// Make sure a unique username and e-mail are used.
-		do {
-			$username = self::$faker->userName();
-		} while ( username_exists( $username ) );
+		$safeEmailDomain = $emailDomain ? $emailDomain : self::$faker->safeEmailDomain();
 
+		// Make sure a unique username and e-mail are used.
 		do {
-			$email = self::$faker->safeEmail();
-		} while ( email_exists( $email ) );
+			$firstname = self::$faker->firstName( self::$faker->randomElement( array( 'male', 'female' ) ) );
+			$lastname  = self::$faker->lastName();
+			$username  = strtolower( "$firstname.$lastname" );
+			$email     = "$username@$safeEmailDomain";
+		} while ( username_exists( $username ) || email_exists( $email ) );
 
-		$firstname   = self::$faker->firstName( self::$faker->randomElement( array( 'male', 'female' ) ) );
-		$lastname    = self::$faker->lastName();
 		$company     = self::$faker->company();
 		$address1    = self::$faker->buildingNumber() . ' ' . self::$faker->streetName();
 		$address2    = self::$faker->streetAddress();