diff --git a/PhpStormStubsMap.php b/PhpStormStubsMap.php
index 1f4d2118..55efda1a 100644
--- a/PhpStormStubsMap.php
+++ b/PhpStormStubsMap.php
@@ -2600,6 +2600,7 @@ const FUNCTIONS = array (
   'imap_mailboxmsginfo' => 'imap/imap.php',
   'imap_mime_header_decode' => 'imap/imap.php',
   'imap_msgno' => 'imap/imap.php',
+  'imap_mutf7_to_utf8' => 'imap/imap.php',
   'imap_myrights' => 'imap/imap.php',
   'imap_num_msg' => 'imap/imap.php',
   'imap_num_recent' => 'imap/imap.php',
@@ -2632,6 +2633,7 @@ const FUNCTIONS = array (
   'imap_utf7_decode' => 'imap/imap.php',
   'imap_utf7_encode' => 'imap/imap.php',
   'imap_utf8' => 'imap/imap.php',
+  'imap_utf8_to_mutf7' => 'imap/imap.php',
   'implode' => 'standard/standard_1.php',
   'import_request_variables' => 'standard/standard_3.php',
   'in_array' => 'standard/standard_8.php',
diff --git a/imap/imap.php b/imap/imap.php
index 57fe366b..d6bf21a8 100644
--- a/imap/imap.php
+++ b/imap/imap.php
@@ -1485,6 +1485,26 @@ function imap_create ($stream_id, $mailbox) {}
  */
 function imap_rename ($stream_id, $old_name, $new_name) {}
 
+/**
+ * Decode a modified UTF-7 string to UTF-8
+ *
+ * @link https://www.php.net/manual/en/function.imap-mutf7-to-utf8.php
+ *
+ * @param string $in
+ * @return string|false
+ */
+function imap_mutf7_to_utf8($in) {}
+
+/**
+ * Encode a UTF-8 string to modified UTF-7
+ *
+ * @link https://www.php.net/manual/en/function.imap-utf8-to-mutf7.php
+ *
+ * @param string $in
+ * @return string|false
+ */
+function imap_utf8_to_mutf7($in) {}
+
 define ('NIL', 0);
 define ('IMAP_OPENTIMEOUT', 1);
 define ('IMAP_READTIMEOUT', 2);