diff --git a/php_v8js_macros.h b/php_v8js_macros.h
index 7f0d019e..c65403e3 100644
--- a/php_v8js_macros.h
+++ b/php_v8js_macros.h
@@ -159,6 +159,9 @@ struct _v8js_process_globals {
 	/* Path to icudtl.dat file */
 	char *icudtl_dat_path;
 
+	/* Number of V8 platform background worker threads */
+	int thread_pool_size;
+
 	std::unique_ptr<v8::Platform> v8_platform;
 };
 
diff --git a/tests/thread_pool_size.phpt b/tests/thread_pool_size.phpt
new file mode 100644
index 00000000..f9cf1412
--- /dev/null
+++ b/tests/thread_pool_size.phpt
@@ -0,0 +1,76 @@
+--TEST--
+v8js.thread_pool_size INI directive validation and lifecycle
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--INI--
+v8js.thread_pool_size=0
+--FILE--
+<?php
+// 1. Initial value
+var_dump(ini_get('v8js.thread_pool_size'));
+
+// 2. Valid values before initialization (including boundaries 0 and 64)
+var_dump(ini_set('v8js.thread_pool_size', '1'));
+var_dump(ini_get('v8js.thread_pool_size'));
+
+var_dump(ini_set('v8js.thread_pool_size', '64'));
+var_dump(ini_get('v8js.thread_pool_size'));
+
+var_dump(ini_set('v8js.thread_pool_size', '0'));
+var_dump(ini_get('v8js.thread_pool_size'));
+
+var_dump(ini_set('v8js.thread_pool_size', '4'));
+var_dump(ini_get('v8js.thread_pool_size'));
+
+// 3. Out-of-range and malformed values (must return false, value remains unchanged)
+var_dump(ini_set('v8js.thread_pool_size', '-1'));
+var_dump(ini_set('v8js.thread_pool_size', '-42'));
+var_dump(ini_set('v8js.thread_pool_size', '65'));
+var_dump(ini_set('v8js.thread_pool_size', '100'));
+var_dump(@ini_set('v8js.thread_pool_size', '-1foo'));
+var_dump(@ini_set('v8js.thread_pool_size', '100M'));
+var_dump(ini_get('v8js.thread_pool_size'));
+
+// 4. Initialize V8 platform by creating an instance
+$v8 = new V8Js();
+var_dump($v8->executeString('1 + 2'));
+
+// 5. Attempts to change setting after initialization must fail
+var_dump(ini_set('v8js.thread_pool_size', '2'));
+var_dump(ini_set('v8js.thread_pool_size', '0'));
+var_dump(ini_set('v8js.thread_pool_size', '64'));
+var_dump(ini_get('v8js.thread_pool_size'));
+
+// 6. Attempts to change setting after destroying instance must still fail
+unset($v8);
+var_dump(ini_set('v8js.thread_pool_size', '8'));
+var_dump(ini_set('v8js.thread_pool_size', '0'));
+var_dump(ini_get('v8js.thread_pool_size'));
+?>
+===EOF===
+--EXPECT--
+string(1) "0"
+string(1) "0"
+string(1) "1"
+string(1) "1"
+string(2) "64"
+string(2) "64"
+string(1) "0"
+string(1) "0"
+string(1) "4"
+bool(false)
+bool(false)
+bool(false)
+bool(false)
+bool(false)
+bool(false)
+string(1) "4"
+int(3)
+bool(false)
+bool(false)
+bool(false)
+string(1) "4"
+bool(false)
+bool(false)
+string(1) "4"
+===EOF===
diff --git a/v8js_main.cc b/v8js_main.cc
index 627949a0..01574c18 100644
--- a/v8js_main.cc
+++ b/v8js_main.cc
@@ -112,11 +112,41 @@ static ZEND_INI_MH(v8js_OnUpdateUseArrayAccess) /* {{{ */
 }
 /* }}} */
 
+static ZEND_INI_MH(v8js_OnUpdateThreadPoolSize) /* {{{ */
+{
+#if PHP_VERSION_ID < 80200
+	zend_long tmp = zend_atol(ZSTR_VAL(new_value), ZSTR_LEN(new_value));
+#else
+	zend_long tmp = zend_ini_parse_quantity_warn(new_value, entry->name);
+#endif
+	/* V8 has hard limit of 16 threads for now, we allow up to 64 */
+	if (tmp < 0 || tmp > 64) {
+		return FAILURE;
+	}
+
+#ifdef ZTS
+	std::lock_guard<std::mutex> lock(v8js_process_globals.lock);
+	if (v8js_process_globals.v8_initialized) {
+		return FAILURE;
+	}
+#else
+	/* V8 already has been initialized -> cannot be changed anymore */
+	if (V8JSG(v8_initialized)) {
+		return FAILURE;
+	}
+#endif
+
+	v8js_process_globals.thread_pool_size = static_cast<int>(tmp);
+	return SUCCESS;
+}
+/* }}} */
+
 ZEND_INI_BEGIN() /* {{{ */
 	ZEND_INI_ENTRY("v8js.flags", NULL, ZEND_INI_ALL, v8js_OnUpdateV8Flags)
 	ZEND_INI_ENTRY("v8js.icudtl_dat_path", NULL, ZEND_INI_ALL, v8js_OnUpdateIcudatPath)
 	ZEND_INI_ENTRY("v8js.use_date", "0", ZEND_INI_ALL, v8js_OnUpdateUseDate)
 	ZEND_INI_ENTRY("v8js.use_array_access", "0", ZEND_INI_ALL, v8js_OnUpdateUseArrayAccess)
+	ZEND_INI_ENTRY("v8js.thread_pool_size", "0", ZEND_INI_ALL, v8js_OnUpdateThreadPoolSize)
 ZEND_INI_END()
 /* }}} */
 
diff --git a/v8js_v8.cc b/v8js_v8.cc
index 467f201b..cba06e21 100644
--- a/v8js_v8.cc
+++ b/v8js_v8.cc
@@ -68,7 +68,11 @@ void v8js_v8_init() /* {{{ */
 #endif
 #endif
 
-	v8js_process_globals.v8_platform = v8::platform::NewDefaultPlatform();
+	if (v8js_process_globals.thread_pool_size > 0) {
+		v8js_process_globals.v8_platform = v8::platform::NewDefaultPlatform(v8js_process_globals.thread_pool_size);
+	} else {
+		v8js_process_globals.v8_platform = v8::platform::NewDefaultPlatform();
+	}
 	v8::V8::InitializePlatform(v8js_process_globals.v8_platform.get());
 
 #ifdef V8_HAS_INITIALIZE_SANDBOX