diff --git a/Zend/Optimizer/zend_func_info.c b/Zend/Optimizer/zend_func_info.c
index 8d39c5c19b..d236d0d02c 100644
--- a/Zend/Optimizer/zend_func_info.c
+++ b/Zend/Optimizer/zend_func_info.c
@@ -451,7 +451,7 @@ static const func_info_t func_infos[] = {
 	F1("mysqli_fetch_field_direct",				MAY_BE_FALSE | MAY_BE_OBJECT),
 	F1("mysqli_fetch_lengths",					MAY_BE_FALSE | MAY_BE_ARRAY | MAY_BE_ARRAY_KEY_LONG | MAY_BE_ARRAY_OF_LONG),
 	F1("mysqli_fetch_row",						MAY_BE_NULL | MAY_BE_ARRAY | MAY_BE_ARRAY_KEY_LONG | MAY_BE_ARRAY_OF_ANY),
-	F1("mysqli_get_client_info",				MAY_BE_NULL | MAY_BE_STRING),
+	F1("mysqli_get_client_info",				MAY_BE_STRING),
 	F1("mysqli_get_host_info",					MAY_BE_STRING),
 	F1("mysqli_get_server_info",				MAY_BE_STRING),
 	F1("mysqli_info",							MAY_BE_NULL | MAY_BE_STRING),
diff --git a/ext/mysqli/mysqli.stub.php b/ext/mysqli/mysqli.stub.php
index f5c34d1654..8e04f41ff6 100644
--- a/ext/mysqli/mysqli.stub.php
+++ b/ext/mysqli/mysqli.stub.php
@@ -683,7 +683,7 @@ function mysqli_get_client_stats(): array {}
 
 function mysqli_get_charset(mysqli $mysql): ?object {}
 
-function mysqli_get_client_info(?mysqli $mysql = null): ?string {}
+function mysqli_get_client_info(?mysqli $mysql = null): string {}
 
 function mysqli_get_client_version(): int {}
 
diff --git a/ext/mysqli/mysqli_arginfo.h b/ext/mysqli/mysqli_arginfo.h
index abf275eb86..2c666a78e0 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: c9f340f48c4414f1b0cfa48ac9b7167a0a6991ef */
+ * Stub hash: 2f96f80badee5623220fd720e91aec7795e32723 */
 
 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)
@@ -150,7 +150,7 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mysqli_get_charset, 0, 1, IS_OBJ
 	ZEND_ARG_OBJ_INFO(0, mysql, mysqli, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mysqli_get_client_info, 0, 0, IS_STRING, 1)
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mysqli_get_client_info, 0, 0, IS_STRING, 0)
 	ZEND_ARG_OBJ_INFO_WITH_DEFAULT_VALUE(0, mysql, mysqli, 1, "null")
 ZEND_END_ARG_INFO()