diff --git a/composer.json b/composer.json
index 049e6e9..48f0ce1 100644
--- a/composer.json
+++ b/composer.json
@@ -2,6 +2,7 @@
 	"name": "humanmade/mercator",
 	"description": "WordPress multisite domain mapping for the modern era.",
 	"homepage": "https://github.com/humanmade/Mercator",
+	"version": "1.0.0",
 	"keywords": [
 		"wordpress"
 	],
diff --git a/mercator.php b/mercator.php
index 35a33aa..6346bea 100644
--- a/mercator.php
+++ b/mercator.php
@@ -14,7 +14,7 @@
 /**
  * Current version of Mercator.
  */
-const VERSION = '0.1';
+const VERSION = '1.0.0';
 
 require __DIR__ . '/class-mapping.php';
 require __DIR__ . '/class-network-mapping.php';
@@ -99,6 +99,11 @@ function startup() {
 		WP_CLI::add_command( 'mercator network-mapping', __NAMESPACE__ . '\\CLI\\Network_Mapping_Command' );
 	}
 
+	/**
+	 * Check the table exists and that we're up to date.
+	 */
+	add_action( 'admin_init', __NAMESPACE__ . '\\check_table', -101 );
+
 	/**
 	 * Fired after Mercator core has been loaded
 	 *
@@ -131,8 +136,6 @@ function check_domain_mapping( $site, $domain ) {
 		return $site;
 	}
 
-	global $wpdb;
-
 	// Grab both WWW and no-WWW
 	if ( strpos( $domain, 'www.' ) === 0 ) {
 		$www = $domain;
@@ -186,10 +189,14 @@ function check_domain_mapping( $site, $domain ) {
 function check_table() {
 	global $wpdb;
 
+	if ( get_option( 'mercator.db.version' ) === VERSION ) {
+		return 'exists';
+	}
+
 	$schema = "CREATE TABLE {$wpdb->dmtable} (
 		id bigint(20) NOT NULL auto_increment,
 		blog_id bigint(20) NOT NULL,
-		domain varchar(255) NOT NULL,
+		domain varchar(191) NOT NULL,
 		active tinyint(4) default 1,
 		PRIMARY KEY  (id),
 		KEY blog_id (blog_id,domain,active),
@@ -219,6 +226,12 @@ function check_table() {
 		return 'exists';
 	}
 
+	// utf8mb4 conversion.
+	maybe_convert_table_to_utf8mb4( $wpdb->dmtable );
+
+	// Update db version option.
+	update_option( 'mercator.db.version', VERSION );
+
 	return 'created';
 }