diff --git a/NEWS b/NEWS
index 78265622e7d7..887ff5b3401d 100644
--- a/NEWS
+++ b/NEWS
@@ -58,6 +58,10 @@ PHP                                                                        NEWS
     left busy for the next fetch, and rows delivered from a result another
     statement took over. (KentarouTakeda)
 
+- PGSQL:
+  . Fixed the class name casing of pg_close_stmt()'s connection parameter.
+    (lacatoire)
+
 - Phar:
   . Fixed Phar archives being automatically detected when ".phar" only occurs
     in a directory name or is not a filename extension in an included file's
diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index 96bf83a35527..f4bdcf3e7f7a 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -2945,7 +2945,7 @@ ZEND_RINIT_FUNCTION(zend_accelerator)
 				zend_reset_cache_vars();
 				zend_accel_hash_clean(&ZCSG(hash));
 
-				if (ZCG(accel_directives).interned_strings_buffer) {
+				if (ZCSG(interned_strings).saved_top) {
 					accel_interned_strings_restore_state();
 				}
 
diff --git a/ext/opcache/zend_accelerator_module.c b/ext/opcache/zend_accelerator_module.c
index 465b15cd9576..a513627414ac 100644
--- a/ext/opcache/zend_accelerator_module.c
+++ b/ext/opcache/zend_accelerator_module.c
@@ -102,6 +102,15 @@ static ZEND_INI_MH(OnUpdateMemoryConsumption)
 
 static ZEND_INI_MH(OnUpdateInternedStringsBuffer)
 {
+	if (accel_startup_ok) {
+		if (strcmp(sapi_module.name, "fpm-fcgi") == 0) {
+			zend_accel_error(ACCEL_LOG_WARNING, "opcache.interned_strings_buffer cannot be changed when OPcache is already set up. Are you using php_admin_value[opcache.interned_strings_buffer] in an individual pool's configuration?\n");
+		} else {
+			zend_accel_error(ACCEL_LOG_WARNING, "opcache.interned_strings_buffer cannot be changed when OPcache is already set up.\n");
+		}
+		return FAILURE;
+	}
+
 	zend_long *p = ZEND_INI_GET_ADDR();
 	zend_long size = zend_ini_parse_quantity_warn(new_value, entry->name);
 
diff --git a/ext/pgsql/pgsql.stub.php b/ext/pgsql/pgsql.stub.php
index 52ddc3b3748a..8c5a7f4c6d98 100644
--- a/ext/pgsql/pgsql.stub.php
+++ b/ext/pgsql/pgsql.stub.php
@@ -956,7 +956,7 @@ function pg_socket_poll($socket, int $read, int $write, int $timeout = -1): int
     function pg_set_chunked_rows_size(PgSql\Connection $connection, int $size): bool {}
 #endif
 #ifdef HAVE_PG_CLOSE_STMT
-    function pg_close_stmt(Pgsql\Connection $connection, string $statement_name): PgSql\Result|false {}
+    function pg_close_stmt(PgSql\Connection $connection, string $statement_name): PgSql\Result|false {}
 #endif
 }
 
diff --git a/ext/pgsql/pgsql_arginfo.h b/ext/pgsql/pgsql_arginfo.h
index 63a1d185d535..974a6e9117cd 100644
--- a/ext/pgsql/pgsql_arginfo.h
+++ b/ext/pgsql/pgsql_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit pgsql.stub.php instead.
- * Stub hash: f25b5a574c96d4bc2f08b8cacab16f499a164a6b */
+ * Stub hash: fa7cd778f4e791b15ffc8f1786384332449bda5a */
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_TYPE_MASK_EX(arginfo_pg_connect, 0, 1, PgSql\\Connection, MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, connection_string, IS_STRING, 0)
@@ -503,7 +503,7 @@ ZEND_END_ARG_INFO()
 
 #if defined(HAVE_PG_CLOSE_STMT)
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_TYPE_MASK_EX(arginfo_pg_close_stmt, 0, 2, PgSql\\Result, MAY_BE_FALSE)
-	ZEND_ARG_OBJ_INFO(0, connection, Pgsql\\Connection, 0)
+	ZEND_ARG_OBJ_INFO(0, connection, PgSql\\Connection, 0)
 	ZEND_ARG_TYPE_INFO(0, statement_name, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 #endif
diff --git a/ext/pgsql/tests/pg_close_stmt_parameter_type.phpt b/ext/pgsql/tests/pg_close_stmt_parameter_type.phpt
new file mode 100644
index 000000000000..c9c6c4f40ad5
--- /dev/null
+++ b/ext/pgsql/tests/pg_close_stmt_parameter_type.phpt
@@ -0,0 +1,22 @@
+--TEST--
+pg_close_stmt(): the connection parameter is typed like every other pgsql function
+--EXTENSIONS--
+pgsql
+--SKIPIF--
+<?php
+if (!function_exists('pg_close_stmt')) die('skip pg_close_stmt() requires libpq >= 17');
+?>
+--FILE--
+<?php
+
+foreach (['pg_close_stmt', 'pg_connect_poll'] as $function) {
+    $parameter = (new ReflectionFunction($function))->getParameters()[0];
+    printf("%-16s %s\n", $function, $parameter->getType());
+}
+
+var_dump((new ReflectionClass(PgSql\Connection::class))->getName());
+?>
+--EXPECT--
+pg_close_stmt    PgSql\Connection
+pg_connect_poll  PgSql\Connection
+string(16) "PgSql\Connection"
diff --git a/sapi/fpm/tests/gh23288-opcache-interned-strings-buffer-pool.phpt b/sapi/fpm/tests/gh23288-opcache-interned-strings-buffer-pool.phpt
new file mode 100644
index 000000000000..8f48b3a8c209
--- /dev/null
+++ b/sapi/fpm/tests/gh23288-opcache-interned-strings-buffer-pool.phpt
@@ -0,0 +1,50 @@
+--TEST--
+FPM: GH-23288 - opcache.interned_strings_buffer overridden per pool must not crash on restart
+--EXTENSIONS--
+opcache
+--SKIPIF--
+<?php include "skipif.inc"; ?>
+--FILE--
+<?php
+
+require_once "tester.inc";
+
+$cfg = <<<EOT
+[global]
+error_log = {{FILE:LOG}}
+[unconfined]
+listen = {{ADDR}}
+pm = static
+pm.max_children = 1
+php_admin_value[opcache.interned_strings_buffer] = 8
+EOT;
+
+$code = <<<EOT
+<?php
+opcache_reset();
+opcache_reset();
+echo "ok";
+EOT;
+
+$opcache = ini_get('extension_dir') . DIRECTORY_SEPARATOR . 'opcache.' . PHP_SHLIB_SUFFIX;
+$extraArgs = is_file($opcache) ? ['-dzend_extension=' . $opcache] : [];
+
+$tester = new FPM\Tester($cfg, $code);
+$tester->start($extraArgs, iniEntries: ['opcache.interned_strings_buffer' => '0']);
+$tester->expectLogStartNotices();
+$tester->request()->expectBody('ok');
+$tester->request()->expectBody('ok');
+$tester->request()->expectBody('ok');
+$tester->terminate();
+$tester->expectLogTerminatingNotices();
+$tester->close();
+
+?>
+Done
+--EXPECT--
+Done
+--CLEAN--
+<?php
+require_once "tester.inc";
+FPM\Tester::clean();
+?>