diff --git a/build/gen_stub.php b/build/gen_stub.php
index 45641f4061b9c..f1d8b43862e62 100755
--- a/build/gen_stub.php
+++ b/build/gen_stub.php
@@ -3282,18 +3282,13 @@ public function getRegistration(array $allConstInfos): string
 
         $code .= "{\n";
 
-        $flagCodes = generateVersionDependentFlagCode("%s", $this->getFlagsByPhpVersion(), $this->phpVersionIdMinimumCompatibility);
-        $flags = implode("", $flagCodes);
-
         $classMethods = ($this->funcInfos === []) ? 'NULL' : "class_{$escapedName}_methods";
         if ($this->type === "enum") {
             $name = addslashes((string) $this->name);
             $backingType = $this->enumBackingType
                 ? $this->enumBackingType->toTypeCode() : "IS_UNDEF";
             $code .= "\tzend_class_entry *class_entry = zend_register_internal_enum(\"$name\", $backingType, $classMethods);\n";
-            if ($flags !== "") {
-                $code .= "\tclass_entry->ce_flags |= $flags\n";
-            }
+            $code .= implode("", generateVersionDependentFlagCode("\tclass_entry->ce_flags = %s;\n", $this->getFlagsByPhpVersion(), $this->phpVersionIdMinimumCompatibility));
         } else {
             $code .= "\tzend_class_entry ce, *class_entry;\n\n";
             if (count($this->name->getParts()) > 1) {
@@ -3310,22 +3305,25 @@ public function getRegistration(array $allConstInfos): string
                     $code .= "#if (PHP_VERSION_ID >= " . PHP_84_VERSION_ID . ")\n";
                 }
 
-                $code .= "\tclass_entry = zend_register_internal_class_with_flags(&ce, " . (isset($this->extends[0]) ? "class_entry_" . str_replace("\\", "_", $this->extends[0]->toString()) : "NULL") . ", " . ($flags ?: 0) . ");\n";
+                $template = "\tclass_entry = zend_register_internal_class_with_flags(&ce, " . (isset($this->extends[0]) ? "class_entry_" . str_replace("\\", "_", $this->extends[0]->toString()) : "NULL") . ", %s);\n";
+                $entries = generateVersionDependentFlagCode($template, $this->getFlagsByPhpVersion(), $this->phpVersionIdMinimumCompatibility ? max($this->phpVersionIdMinimumCompatibility, PHP_84_VERSION_ID) : null);
+                if ($entries !== []) {
+                    $code .= implode("", $entries);
+                } else {
+                    $code .= sprintf($template, "0");
+                }
 
                 if (!$php84MinimumCompatibility) {
                     $code .= "#else\n";
 
                     $code .= "\tclass_entry = zend_register_internal_class_ex(&ce, " . (isset($this->extends[0]) ? "class_entry_" . str_replace("\\", "_", $this->extends[0]->toString()) : "NULL") . ");\n";
-                    if ($flags !== "") {
-                        $code .= "\tclass_entry->ce_flags |= $flags;\n";
-                    }
+                    $code .= implode("", generateVersionDependentFlagCode("\tclass_entry->ce_flags |= %s;\n", $this->getFlagsByPhpVersion(), $this->phpVersionIdMinimumCompatibility));
                     $code .= "#endif\n";
                 }
             } else {
                 $code .= "\tclass_entry = zend_register_internal_interface(&ce);\n";
-                if ($flags !== "") {
-                    $code .= "\tclass_entry->ce_flags |= $flags\n";
-                }
+                $code .= implode("", generateVersionDependentFlagCode("\tclass_entry->ce_flags |= %s;\n", $this->getFlagsByPhpVersion(), $this->phpVersionIdMinimumCompatibility));
+
             }
         }
 
diff --git a/ext/zend_test/test.c b/ext/zend_test/test.c
index dbad83fb0e843..d52b8aa0cd172 100644
--- a/ext/zend_test/test.c
+++ b/ext/zend_test/test.c
@@ -54,6 +54,7 @@ ZEND_DECLARE_MODULE_GLOBALS(zend_test)
 static zend_class_entry *zend_test_interface;
 static zend_class_entry *zend_test_class;
 static zend_class_entry *zend_test_child_class;
+static zend_class_entry *zend_test_gen_stub_flag_compatibility_test;
 static zend_class_entry *zend_attribute_test_class;
 static zend_class_entry *zend_test_trait;
 static zend_class_entry *zend_test_attribute;
@@ -1271,6 +1272,8 @@ PHP_MINIT_FUNCTION(zend_test)
 	memcpy(&zend_test_class_handlers, &std_object_handlers, sizeof(zend_object_handlers));
 	zend_test_class_handlers.get_method = zend_test_class_method_get;
 
+	zend_test_gen_stub_flag_compatibility_test = register_class_ZendTestGenStubFlagCompatibilityTest();
+
 	zend_attribute_test_class = register_class_ZendAttributeTest();
 
 	zend_test_trait = register_class__ZendTestTrait();
diff --git a/ext/zend_test/test.stub.php b/ext/zend_test/test.stub.php
index fbfd93da40975..213c1b3f57476 100644
--- a/ext/zend_test/test.stub.php
+++ b/ext/zend_test/test.stub.php
@@ -85,6 +85,13 @@ class _ZendTestChildClass extends _ZendTestClass
         public function returnsThrowable(): Exception {}
     }
 
+    /**
+     * @not-serializable
+     */
+    final class ZendTestGenStubFlagCompatibilityTest {
+
+    }
+
     class ZendAttributeTest {
         /** @var int */
         #[ZendTestRepeatableAttribute]
diff --git a/ext/zend_test/test_arginfo.h b/ext/zend_test/test_arginfo.h
index eb83d34fa1f59..9888ba39c14e4 100644
--- a/ext/zend_test/test_arginfo.h
+++ b/ext/zend_test/test_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: a7b5de3e4868f9a4aef78da6b98bbce882e129a9 */
+ * Stub hash: 20a58913caf419fb60a3bc9cf275db605e2c3b0f */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_zend_test_array_return, 0, 0, IS_ARRAY, 0)
 ZEND_END_ARG_INFO()
@@ -774,6 +774,25 @@ static zend_class_entry *register_class__ZendTestChildClass(zend_class_entry *cl
 	return class_entry;
 }
 
+static zend_class_entry *register_class_ZendTestGenStubFlagCompatibilityTest(void)
+{
+	zend_class_entry ce, *class_entry;
+
+	INIT_CLASS_ENTRY(ce, "ZendTestGenStubFlagCompatibilityTest", NULL);
+#if (PHP_VERSION_ID >= 80400)
+	class_entry = zend_register_internal_class_with_flags(&ce, NULL, ZEND_ACC_FINAL|ZEND_ACC_NOT_SERIALIZABLE);
+#else
+	class_entry = zend_register_internal_class_ex(&ce, NULL);
+#if (PHP_VERSION_ID >= 80100)
+	class_entry->ce_flags |= ZEND_ACC_FINAL|ZEND_ACC_NOT_SERIALIZABLE;
+#elif (PHP_VERSION_ID >= 80000)
+	class_entry->ce_flags |= ZEND_ACC_FINAL;
+#endif
+#endif
+
+	return class_entry;
+}
+
 static zend_class_entry *register_class_ZendAttributeTest(void)
 {
 	zend_class_entry ce, *class_entry;