diff --git a/UPGRADING b/UPGRADING
index 670cac49ea1..6589f4d12b5 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -704,6 +704,10 @@ PHP 8.4 UPGRADE NOTES
 - MBString:
   . Unicode data tables have been updated to Unicode 15.1.
 
+- mysqli:
+  . The unused and undocumented constant MYSQLI_SET_CHARSET_DIR
+    has been removed.
+
 - OpenSSL:
   . The OpenSSL extension now requires at least OpenSSL 1.1.1.
 
diff --git a/ext/mysqli/mysqli.stub.php b/ext/mysqli/mysqli.stub.php
index d7555560a66..fed02e14b02 100644
--- a/ext/mysqli/mysqli.stub.php
+++ b/ext/mysqli/mysqli.stub.php
@@ -436,11 +436,6 @@ const MYSQLI_TYPE_BIT = UNKNOWN;
  * @cvalue MYSQL_SET_CHARSET_NAME
  */
 const MYSQLI_SET_CHARSET_NAME = UNKNOWN;
-/**
- * @var int
- * @cvalue MYSQL_SET_CHARSET_DIR
- */
-const MYSQLI_SET_CHARSET_DIR = UNKNOWN;
 
 /* bind support */
 /**
diff --git a/ext/mysqli/mysqli_arginfo.h b/ext/mysqli/mysqli_arginfo.h
index 293db93295f..3390016d4f4 100644
--- a/ext/mysqli/mysqli_arginfo.h
+++ b/ext/mysqli/mysqli_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 5cdfeec10f0f92e3e2f9d2df572b2681b208449d */
+ * Stub hash: eb43a01e76fc18bc56572129be8d6dfce1a1e52a */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_mysqli_affected_rows, 0, 1, MAY_BE_LONG|MAY_BE_STRING)
 	ZEND_ARG_OBJ_INFO(0, mysql, mysqli, 0)
@@ -1127,7 +1127,6 @@ static void register_mysqli_symbols(int module_number)
 	REGISTER_LONG_CONSTANT("MYSQLI_TYPE_NEWDECIMAL", FIELD_TYPE_NEWDECIMAL, CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("MYSQLI_TYPE_BIT", FIELD_TYPE_BIT, CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("MYSQLI_SET_CHARSET_NAME", MYSQL_SET_CHARSET_NAME, CONST_PERSISTENT);
-	REGISTER_LONG_CONSTANT("MYSQLI_SET_CHARSET_DIR", MYSQL_SET_CHARSET_DIR, CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("MYSQLI_NO_DATA", MYSQL_NO_DATA, CONST_PERSISTENT | CONST_DEPRECATED);
 #if defined(MYSQL_DATA_TRUNCATED)
 	REGISTER_LONG_CONSTANT("MYSQLI_DATA_TRUNCATED", MYSQL_DATA_TRUNCATED, CONST_PERSISTENT | CONST_DEPRECATED);
diff --git a/ext/mysqli/tests/mysqli_constants.phpt b/ext/mysqli/tests/mysqli_constants.phpt
index c228e1aafb6..20def1043d3 100644
--- a/ext/mysqli/tests/mysqli_constants.phpt
+++ b/ext/mysqli/tests/mysqli_constants.phpt
@@ -82,7 +82,6 @@ $expected_constants = array(
     "MYSQLI_REPORT_ERROR"				=> true,
     "MYSQLI_REPORT_OFF"					=> true,
     "MYSQLI_SET_CHARSET_NAME"			=> true,
-    "MYSQLI_SET_CHARSET_DIR"			=> true,
     "MYSQLI_REFRESH_GRANT"				=> true,
     "MYSQLI_REFRESH_LOG"				=> true,
     "MYSQLI_REFRESH_TABLES"				=> true,