diff --git a/ErrorReport2.php b/ErrorReport2.php
index 27b4e21..2211736 100644
--- a/ErrorReport2.php
+++ b/ErrorReport2.php
@@ -9,10 +9,32 @@
  * ErrorReport2 Model
  *
  * @package ErrorReport2
- * @version 2.0.0
+ * @version 2.0.2
  */
 final class ErrorReport2 extends SuperStorage
-{}
+{
+	public static function databaseTableVersion() : ?int
+	{
+		$storage_engine = self::storageEngine();
+		$database = $storage_engine->database();
+		$database_name = $storage_engine->database()->getDatabaseConfig()->getDatabase();
+		$table_name = $storage_engine->tableName();
+		$query = 'SHOW TABLE STATUS FROM ' . $database_name . ' LIKE "' . $table_name . '"';
+
+		$results = $database->query($query);
+		if ($results = mysqli_fetch_object($results)) {
+			$table_comment = $results->Comment;
+			$comments = preg_split('/^\\\\,/', $table_comment);
+			foreach ($comments as $comment) {
+				if (strncmp($comment, 'er2-db-vers:', 12) === 0) {
+					return (int)substr($comment, 12);
+				}
+			}
+		}
+
+		return null;
+	}
+}
 
 
 ?>
\ No newline at end of file
diff --git a/ErrorReport2Server.php b/ErrorReport2Server.php
index 7cfb2fe..482ae84 100644
--- a/ErrorReport2Server.php
+++ b/ErrorReport2Server.php
@@ -13,11 +13,13 @@
  * ErrorReport2 Server
  *
  * @package ErrorReport2
- * @version 2.0.1
+ * @version 2.0.2
  */
 final class ErrorReport2Server extends Controller
 {
-	private const ER2_VERSION = '2.0.1';
+	private const ER2_VERSION = '2.0.2';
+
+	public const REQUIRED_DATABASE_VERSION = 2;
 
 	private const ERROR_RESPONSE_CODE = 400;
 	private const SUCCESS_RESPONSE_CODE = 201;
@@ -60,6 +62,15 @@ public function __construct(string $method_name, Request $request)
 		}
 
 		$this->config = $er2_server_config;
+
+		if (!self::checkDatabaseVersion()) {
+			throw new \RuntimeException('Unmatching database version');
+		}
+	}
+
+	public static function checkDatabaseVersion() : bool
+	{
+		return ErrorReport2::databaseTableVersion() === self::REQUIRED_DATABASE_VERSION;
 	}
 
 	private function checkHttpMethod(Request $request) : void
diff --git a/README.md b/README.md
index 432556d..9a6c6bc 100644
--- a/README.md
+++ b/README.md
@@ -49,6 +49,12 @@ __Example for 6.:__
 $config->setER2Config((new \ErrorReport2\ErrorReport2ServerConfig())->addToken('3915753d8765a0'));
 ```
 
+## Update
+When ER2 is included as git submodule, update the submodule.
+Some updates come with database structure changes.
+The database updates (sql batch files) can be found in db-directory.
+They must be executed in the database manually.
+
 ## Configuration
 
 ### Required configuration
diff --git a/db/update_201->202.sql b/db/update_201->202.sql
new file mode 100644
index 0000000..32bf385
--- /dev/null
+++ b/db/update_201->202.sql
@@ -0,0 +1,5 @@
+-- Error Report 2 Module
+-- Update from ER2 2.0.1 to 2.0.2
+
+ALTER TABLE ErrorReport2 CHANGE COLUMN `debug_mode` `debug_mode` tinyint unsigned COMMENT 'BOOL';
+ALTER TABLE ErrorReport2 COMMENT = 'er2-db-vers:2';
diff --git a/er2.sql b/er2.sql
index d56cddd..63f5ec0 100644
--- a/er2.sql
+++ b/er2.sql
@@ -1,5 +1,5 @@
 -- Error Report 2 Module
--- Version 2.0.1
+-- Version 2.0.2
 
 
 CREATE TABLE ErrorReport2 (
@@ -17,7 +17,7 @@ CREATE TABLE ErrorReport2 (
 	`php_version` varchar(20) NOT NULL,
 	`php_mode` varchar(30) NOT NULL,
 	`php_mem_usage` bigint unsigned NOT NULL,
-	`debug_mode` tinyint unsigned NOT NULL COMMENT 'BOOL',
+	`debug_mode` tinyint unsigned COMMENT 'BOOL',
 	`request_method` enum('CONNECT', 'DELETE', 'GET', 'HEAD', 'OPTIONS', 'PATCH', 'POST', 'PUT', 'TRACE') NOT NULL,
 	`request_domain` varchar(255) NOT NULL,
 	`request_subdomain` varchar(255) NOT NULL,
@@ -33,4 +33,4 @@ CREATE TABLE ErrorReport2 (
 	`session` text,
 	`errors` text,
 	`throwable` text
-) ENGINE = InnoDB;
+) ENGINE = InnoDB, COMMENT = 'er2-db-vers:2';