diff --git a/includes/class-command-base.php b/includes/class-command-base.php
index fce37d3..f2ab831 100644
--- a/includes/class-command-base.php
+++ b/includes/class-command-base.php
@@ -34,9 +34,10 @@ abstract protected function name(): string;
 	/**
 	 * This class must be invocable.
 	 *
-	 * @param array $args An array of arguments might be provided.
+	 * @param array $args Optional. Command arguments.
+	 * @param array $assoc_args Optional. Associative array of command options.
 	 */
-	abstract public function __invoke( array $args = array() );
+	abstract public function __invoke( array $args = array(), array $assoc_args = array() );
 
 	/**
 	 * Registers this command.
diff --git a/includes/class-installer.php b/includes/class-installer.php
index ff09c4d..831b112 100644
--- a/includes/class-installer.php
+++ b/includes/class-installer.php
@@ -90,21 +90,25 @@ private function update_file_string_replacements() {
 
 	/**
 	 * Installs theme files.
+	 *
+	 * @param bool $force (Optional) Whether theme files will be overidden. If omitted, theme files will only be created if they do not exist. Defaults to false if not specified.
 	 */
-	public function install() {
-		$this->copy_theme_files();
+	public function install( bool $force = false ) {
+		$this->copy_theme_files( $force );
 		new All_Blocks_Scss_File_Generator( $this->theme_name, $this->message_handler );
 		new Asset_Builder( $this->theme_name, $this->message_handler );
 	}
 
 	/**
 	 * Copies theme files from the theme-template directory into the specified location.
+	 *
+	 * @param bool $force (Optional) Whether theme files will be overidden. If omitted, theme files will only be created if they do not exist. Defaults to false if not specified.
 	 */
-	private function copy_theme_files() {
+	private function copy_theme_files( bool $force = false ) {
 		Helpers::copy_directory(
 			__DIR__ . '/../theme-template',
 			get_theme_root() . '/' . $this->theme_name,
-			true,
+			! $force,
 			function ( string $source_file_path, $destination_file_path ) {
 				$this->file_string_replacer->replace( $destination_file_path );
 			}
diff --git a/includes/commands/class-build-command.php b/includes/commands/class-build-command.php
index 7b9bb22..1b6251e 100644
--- a/includes/commands/class-build-command.php
+++ b/includes/commands/class-build-command.php
@@ -36,8 +36,9 @@ protected function name(): string {
 	 *     $ wp creode-theme:build
 	 *
 	 * @param array $args Not used.
+	 * @param array $assoc_args Not used.
 	 */
-	public function __invoke( array $args = array() ) {
+	public function __invoke( array $args = array(), array $assoc_args = array() ) {
 		$message_handler = new Command_Message_Handler();
 
 		try {
diff --git a/includes/commands/class-install-theme-command.php b/includes/commands/class-install-theme-command.php
index 6f664b2..e10b393 100644
--- a/includes/commands/class-install-theme-command.php
+++ b/includes/commands/class-install-theme-command.php
@@ -36,6 +36,10 @@ protected function name(): string {
 	 * [<theme-directory>]
 	 * : The directory name of the theme to install files to.
 	 *   If omitted, the active theme will be used.
+	 * [--force]
+	 * : Whether theme files will be overidden.
+	 *   If omitted, theme files will only be created if they do not exist.
+	 *   Defaults to false if not specified.
 	 *
 	 * ## EXAMPLES
 	 *
@@ -46,13 +50,14 @@ protected function name(): string {
 	 *     $ wp creode-theme:install my-child-theme
 	 *
 	 * @param array $args Optional. Command arguments. [<theme-directory>].
+	 * @param array $assoc_args Optional. Associative array of command options. ['force' => bool].
 	 */
-	public function __invoke( array $args = array() ) {
+	public function __invoke( array $args = array(), array $assoc_args = array() ) {
 		$theme_name = isset( $args[0] ) ? $args[0] : null;
 
 		try {
 			$installer = new Installer( $theme_name, new Command_Message_Handler() );
-			$installer->install();
+			$installer->install( ! empty( $assoc_args['force'] ) );
 		} catch ( Exception $e ) {
 			WP_CLI::error( $e->getMessage() );
 		}