diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 06b5b1ebf6..b6f9d39bc7 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -2616,10 +2616,10 @@ function wp_ext2type( $ext ) {
  * @param string   $filename File name or path.
  * @param string[] $mimes    Optional. Array of mime types keyed by their file extension regex.
  * @return array {
- *     Values with extension first and mime type.
+ *     Values for the extension and mime type.
  *
- *     @type string $0 File extension.
- *     @type string $1 File mime type.
+ *     @type string|false $0 File extension, or false if the file doesn't match a mime type.
+ *     @type string|false $1 File mime type, or false if the file doesn't match a mime type.
  * }
  */
 function wp_check_filetype( $filename, $mimes = null ) {
@@ -2657,8 +2657,13 @@ function wp_check_filetype( $filename, $mimes = null ) {
  * @param string   $filename The name of the file (may differ from $file due to $file being
  *                           in a tmp directory).
  * @param string[] $mimes    Optional. Array of mime types keyed by their file extension regex.
- * @return array Values for the extension, MIME, and either a corrected filename or false
- *               if original $filename is valid.
+ * @return array {
+ *     Values for the extension, mime type, and corrected filename.
+ *
+ *     @type string|false $0 File extension, or false if the file doesn't match a mime type.
+ *     @type string|false $1 File mime type, or false if the file doesn't match a mime type.
+ *     @type string|false $2 File name with its correct extension, or false if it cannot be determined.
+ * }
  */
 function wp_check_filetype_and_ext( $file, $filename, $mimes = null ) {
 	$proper_filename = false;
@@ -2814,8 +2819,13 @@ function wp_check_filetype_and_ext( $file, $filename, $mimes = null ) {
 	 * @since 3.0.0
 	 * @since 5.1.0 The $real_mime parameter was added.
 	 *
-	 * @param array       $wp_check_filetype_and_ext File data array containing 'ext', 'type', and
-	 *                                               'proper_filename' keys.
+	 * @param array       $wp_check_filetype_and_ext {
+	 *     Values for the extension, mime type, and corrected filename.
+	 *
+	 *     @type string|false $0 File extension, or false if the file doesn't match a mime type.
+	 *     @type string|false $1 File mime type, or false if the file doesn't match a mime type.
+	 *     @type string|false $2 File name with its correct extension, or false if it cannot be determined.
+	 * }
 	 * @param string      $file                      Full path to the file.
 	 * @param string      $filename                  The name of the file (may differ from $file due to
 	 *                                               $file being in a tmp directory).