diff --git a/composer.json b/composer.json
index 3605a8d0..10a35ef2 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
         }
     ],
     "require": {
-        "wp-cli/wp-cli": "^2.12"
+        "wp-cli/wp-cli": "^2.13"
     },
     "require-dev": {
         "wp-cli/extension-command": "^1.2 || ^2",
diff --git a/src/WP_CLI/Fetchers/UnfilteredPlugin.php b/src/WP_CLI/Fetchers/UnfilteredPlugin.php
index 2cac264e..4076178b 100644
--- a/src/WP_CLI/Fetchers/UnfilteredPlugin.php
+++ b/src/WP_CLI/Fetchers/UnfilteredPlugin.php
@@ -9,6 +9,7 @@
  * `all_plugins` filter, so that plugins cannot hide themselves from the
  * checks.
  *
+ * @extends Base<object{name: string, file: string}>
  */
 class UnfilteredPlugin extends Base {
 
@@ -22,9 +23,11 @@ class UnfilteredPlugin extends Base {
 	 *
 	 * @param string|int $name
 	 *
-	 * @return object|false
+	 * @return object{name: string, file: string}|false
 	 */
 	public function get( $name ) {
+		$name = (string) $name;
+
 		foreach ( get_plugins() as $file => $_ ) {
 			if ( "{$name}.php" === $file ||
 				( $name && $file === $name ) ||