diff --git a/features/transient.feature b/features/transient.feature
index fcbd9d8ead..064d4d8836 100644
--- a/features/transient.feature
+++ b/features/transient.feature
@@ -54,3 +54,32 @@ Feature: Manage WordPress transient cache
       """
       Success: Transient deleted.
       """
+
+  Scenario: Transient delete and other flags
+    Given a WP install
+
+    When I try `wp transient delete`
+    Then STDERR should be:
+      """
+      Error: Please specify transient key, or use --all or --expired.
+      """
+
+    When I run `wp transient set foo bar`
+    And I run `wp transient set foo2 bar2`
+    And I run `wp transient delete --all`
+    Then STDOUT should contain:
+      """
+      transients deleted from the database.
+      """
+
+    When I try `wp transient get foo`
+    Then STDERR should be:
+      """
+      Warning: Transient with key "foo" is not set.
+      """
+
+    When I try `wp transient get foo2`
+    Then STDERR should be:
+      """
+      Warning: Transient with key "foo2" is not set.
+      """
diff --git a/php/WP_CLI/Runner.php b/php/WP_CLI/Runner.php
index 031b1bd2ef..a292884a33 100644
--- a/php/WP_CLI/Runner.php
+++ b/php/WP_CLI/Runner.php
@@ -485,6 +485,18 @@ private static function back_compat_conversions( $args, $assoc_args ) {
 			$assoc_args['all'] = true;
 		}
 
+		// transient delete-expired  ->  transient delete --expired
+		if ( count( $args ) > 1 && 'transient' === $args[0] && 'delete-expired' === $args[1] ) {
+			$args[1] = 'delete';
+			$assoc_args['expired'] = true;
+		}
+
+		// transient delete-all  ->  transient delete --all
+		if ( count( $args ) > 1 && 'transient' === $args[0] && 'delete-all' === $args[1] ) {
+			$args[1] = 'delete';
+			$assoc_args['all'] = true;
+		}
+
 		// plugin scaffold  ->  scaffold plugin
 		if ( array( 'plugin', 'scaffold' ) == array_slice( $args, 0, 2 ) ) {
 			list( $args[0], $args[1] ) = array( $args[1], $args[0] );
diff --git a/php/commands/transient.php b/php/commands/transient.php
index d68f4950ce..06cff3ea6c 100644
--- a/php/commands/transient.php
+++ b/php/commands/transient.php
@@ -5,24 +5,24 @@
  *
  * ## EXAMPLES
  *
- *     # Set transient
+ *     # Set transient.
  *     $ wp transient set sample_key "test data" 3600
  *     Success: Transient added.
  *
- *     # Get transient
+ *     # Get transient.
  *     $ wp transient get sample_key
  *     test data
  *
- *     # Delete transient
+ *     # Delete transient.
  *     $ wp transient delete sample_key
  *     Success: Transient deleted.
  *
- *     # Delete expired transients
- *     $ wp transient delete-expired
+ *     # Delete expired transients.
+ *     $ wp transient delete --expired
  *     Success: 12 expired transients deleted from the database.
  *
- *     # Delete all transients
- *     $ wp transient delete-all
+ *     # Delete all transients.
+ *     $ wp transient delete --all
  *     Success: 14 transients deleted from the database.
  */
 class Transient_Command extends WP_CLI_Command {
@@ -111,21 +111,53 @@ public function set( $args, $assoc_args ) {
 	 *
 	 * ## OPTIONS
 	 *
-	 * <key>
+	 * [<key>]
 	 * : Key for the transient.
 	 *
 	 * [--network]
 	 * : Delete the value of a network transient, instead of that on a single site.
 	 *
+	 * [--all]
+	 * : Delete all transients.
+	 *
+	 * [--expired]
+	 * : Delete all expired transients.
+	 *
 	 * ## EXAMPLES
 	 *
+	 *     # Delete transient.
 	 *     $ wp transient delete sample_key
 	 *     Success: Transient deleted.
+	 *
+	 *     # Delete expired transients.
+	 *     $ wp transient delete --expired
+	 *     Success: 12 expired transients deleted from the database.
+	 *
+	 *     # Delete all transients.
+	 *     $ wp transient delete --all
+	 *     Success: 14 transients deleted from the database.
 	 */
 	public function delete( $args, $assoc_args ) {
-		list( $key ) = $args;
+		$key = ( ! empty( $args ) ) ? $args[0] : NULL;
+
+		$all = \WP_CLI\Utils\get_flag_value( $assoc_args, 'all' );
+		$expired = \WP_CLI\Utils\get_flag_value( $assoc_args, 'expired' );
+
+		if ( true === $all ) {
+			$this->delete_all();
+			return;
+		}
+		else if ( true === $expired ) {
+			$this->delete_expired();
+			return;
+		}
+
+		if ( ! $key ) {
+			WP_CLI::error( 'Please specify transient key, or use --all or --expired.' );
+		}
 
 		$func = \WP_CLI\Utils\get_flag_value( $assoc_args, 'network' ) ? 'delete_site_transient' : 'delete_transient';
+
 		if ( $func( $key ) ) {
 			WP_CLI::success( 'Transient deleted.' );
 		} else {
@@ -158,15 +190,8 @@ public function type() {
 
 	/**
 	 * Delete all expired transients.
-	 *
-	 * ## EXAMPLES
-	 *
-	 *     $ wp transient delete-expired
-	 *     Success: 12 expired transients deleted from the database.
-	 *
-	 * @subcommand delete-expired
 	 */
-	public function delete_expired() {
+	private function delete_expired() {
 		global $wpdb, $_wp_using_ext_object_cache;
 
 		// Always delete all transients from DB too.
@@ -192,15 +217,8 @@ public function delete_expired() {
 
 	/**
 	 * Delete all transients.
-	 *
-	 * ## EXAMPLES
-	 *
-	 *     $ wp transient delete-all
-	 *     Success: 14 transients deleted from the database.
-	 *
-	 * @subcommand delete-all
 	 */
-	public function delete_all() {
+	private function delete_all() {
 		global $wpdb, $_wp_using_ext_object_cache;
 
 		// Always delete all transients from DB too.