diff --git a/ext/mysqli/mysqli.stub.php b/ext/mysqli/mysqli.stub.php
index 189fb144436..1e5d73b4daa 100644
--- a/ext/mysqli/mysqli.stub.php
+++ b/ext/mysqli/mysqli.stub.php
@@ -87,7 +87,7 @@ class mysqli
     public function get_charset() {}
 
     /**
-     * @return string|null
+     * @return string
      * @alias mysqli_get_client_info
      */
     public function get_client_info() {}
@@ -601,7 +601,7 @@ 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 85603a6cb24..934c0a7b3db 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: b801127d89f2a392476c71bef16f43c78d82dfd7 */
+ * Stub hash: 04fabe8f7b61ccf36e8ed383396bd4b56e11dd25 */
 
 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)
@@ -146,7 +146,7 @@ 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()
 
diff --git a/ext/opcache/Optimizer/zend_func_info.c b/ext/opcache/Optimizer/zend_func_info.c
index 18268e39385..ae0521cbd9e 100644
--- a/ext/opcache/Optimizer/zend_func_info.c
+++ b/ext/opcache/Optimizer/zend_func_info.c
@@ -475,7 +475,7 @@ 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),