diff --git a/phpBB/phpbb/console/command/db/list_command.php b/phpBB/phpbb/console/command/db/list_command.php
index dfec5c7da2..708107b592 100644
--- a/phpBB/phpbb/console/command/db/list_command.php
+++ b/phpBB/phpbb/console/command/db/list_command.php
@@ -39,12 +39,6 @@ class list_command extends \phpbb\console\command\db\migration_command
 
 		foreach ($this->load_migrations() as $name)
 		{
-			// Ignore non-migration files
-			if (\phpbb\db\migrator::is_migration($name) === false)
-			{
-				continue;
-			}
-
 			if ($this->migrator->migration_state($name) !== false)
 			{
 				$installed[] = $name;
diff --git a/phpBB/phpbb/console/command/db/migration_command.php b/phpBB/phpbb/console/command/db/migration_command.php
index d44ef8c5cb..b951560588 100644
--- a/phpBB/phpbb/console/command/db/migration_command.php
+++ b/phpBB/phpbb/console/command/db/migration_command.php
@@ -45,7 +45,7 @@ abstract class migration_command extends \phpbb\console\command\command
 
 		$this->migrator->set_migrations($migrations);
 
-		return $migrations;
+		return $this->migrator->get_migrations();
 	}
 
 	protected function finalise_update()
diff --git a/phpBB/phpbb/db/migrator.php b/phpBB/phpbb/db/migrator.php
index 8f3b860b93..a1e93942cd 100644
--- a/phpBB/phpbb/db/migrator.php
+++ b/phpBB/phpbb/db/migrator.php
@@ -170,9 +170,27 @@ class migrator
 	*/
 	public function set_migrations($class_names)
 	{
+		foreach ($class_names as $key => $class)
+		{
+			if (!self::is_migration($class))
+			{
+				unset($class_names[$key]);
+			}
+		}
+
 		$this->migrations = $class_names;
 	}
 
+	/**
+	 * Get the list of available migration class names
+	 *
+	 * @return array Array of all migrations available to be run
+	 */
+	public function get_migrations()
+	{
+		return $this->migrations;
+	}
+
 	/**
 	* Runs a single update step from the next migration to be applied.
 	*
@@ -226,7 +244,7 @@ class migrator
 	*/
 	protected function try_apply($name)
 	{
-		if (!self::is_migration($name))
+		if (!class_exists($name))
 		{
 			$this->output_handler->write(array('MIGRATION_NOT_VALID', $name), migrator_output_handler_interface::VERBOSITY_DEBUG);
 			return false;
@@ -401,7 +419,7 @@ class migrator
 	*/
 	protected function try_revert($name)
 	{
-		if (!self::is_migration($name))
+		if (!class_exists($name))
 		{
 			return false;
 		}
@@ -719,7 +737,7 @@ class migrator
 			return false;
 		}
 
-		if (!self::is_migration($name))
+		if (!class_exists($name))
 		{
 			return $name;
 		}
diff --git a/phpBB/phpbb/extension/base.php b/phpBB/phpbb/extension/base.php
index a7531350f7..c7778cfed1 100644
--- a/phpBB/phpbb/extension/base.php
+++ b/phpBB/phpbb/extension/base.php
@@ -73,9 +73,7 @@ class base implements \phpbb\extension\extension_interface
 	*/
 	public function enable_step($old_state)
 	{
-		$migrations = $this->get_migration_file_list();
-
-		$this->migrator->set_migrations($migrations);
+		$this->get_migration_file_list();
 
 		$this->migrator->update();
 
@@ -103,8 +101,6 @@ class base implements \phpbb\extension\extension_interface
 	{
 		$migrations = $this->get_migration_file_list();
 
-		$this->migrator->set_migrations($migrations);
-
 		foreach ($migrations as $migration)
 		{
 			while ($this->migrator->migration_state($migration) !== false)
@@ -137,16 +133,9 @@ class base implements \phpbb\extension\extension_interface
 
 		$migrations = $this->extension_finder->get_classes_from_files($migrations);
 
-		// Unset classes that are not a valid migration
-		foreach ($migrations as $key => $migration)
-		{
-			if (\phpbb\db\migrator::is_migration($migration) === true)
-			{
-				continue;
-			}
+		$this->migrator->set_migrations($migrations);
 
-			unset($migrations[$key]);
-		}
+		$migrations = $this->migrator->get_migrations();
 
 		return $migrations;
 	}
diff --git a/phpBB/phpbb/install/module/update_database/task/update.php b/phpBB/phpbb/install/module/update_database/task/update.php
index eb9bdc8138..4b2baf2c23 100644
--- a/phpBB/phpbb/install/module/update_database/task/update.php
+++ b/phpBB/phpbb/install/module/update_database/task/update.php
@@ -139,17 +139,8 @@ class update extends task_base
 			->extension_directory('/migrations')
 			->get_classes();
 
-		// Unset classes that are not a valid migration
-		foreach ($migrations as $key => $migration_class)
-		{
-			if (\phpbb\db\migrator::is_migration($migration_class) === false)
-			{
-				unset($migrations[$key]);
-			}
-		}
-
 		$this->migrator->set_migrations($migrations);
-		$migration_count = count($migrations);
+		$migration_count = count($this->migrator->get_migrations());
 		$this->iohandler->set_task_count($migration_count, true);
 		$progress_count = $this->installer_config->get('database_update_count', 0);
 
diff --git a/tests/mock/migrator.php b/tests/mock/migrator.php
index 293f115335..4d1aca0a0a 100644
--- a/tests/mock/migrator.php
+++ b/tests/mock/migrator.php
@@ -21,10 +21,6 @@ class phpbb_mock_migrator extends \phpbb\db\migrator
 	{
 	}
 
-	public function set_migrations($class_names)
-	{
-	}
-
 	public function update()
 	{
 	}