diff --git a/NEWS b/NEWS
index 0eb3d46ee0527..924a7b5418575 100644
--- a/NEWS
+++ b/NEWS
@@ -59,6 +59,10 @@ PHP                                                                        NEWS
 - Random:
   . Fix Randomizer::__serialize() w.r.t. INDIRECTs. (nielsdos)
 
+- Reflection:
+  . Fixed bug GH-20217 (ReflectionClass::isIterable() incorrectly returns true
+    for classes with property hooks). (alexandre-daubois)
+
 - SimpleXML:
   . Partially fixed bug GH-16317 (SimpleXML does not allow __debugInfo() overrides
     to work). (nielsdos)
diff --git a/ext/reflection/php_reflection.c b/ext/reflection/php_reflection.c
index f79d8a5181dda..e718b1815fb36 100644
--- a/ext/reflection/php_reflection.c
+++ b/ext/reflection/php_reflection.c
@@ -5696,7 +5696,8 @@ ZEND_METHOD(ReflectionClass, isIterable)
 		RETURN_FALSE;
 	}
 
-	RETURN_BOOL(ce->get_iterator || instanceof_function(ce, zend_ce_traversable));
+	RETURN_BOOL((ce->get_iterator && ce->get_iterator != zend_hooked_object_get_iterator)
+				|| instanceof_function(ce, zend_ce_traversable));
 }
 /* }}} */
 
diff --git a/ext/reflection/tests/ReflectionClass_isIterable_gh20217.phpt b/ext/reflection/tests/ReflectionClass_isIterable_gh20217.phpt
new file mode 100644
index 0000000000000..f64fc1efcd414
--- /dev/null
+++ b/ext/reflection/tests/ReflectionClass_isIterable_gh20217.phpt
@@ -0,0 +1,38 @@
+--TEST--
+GH-20217 (ReflectionClass::isIterable() should return false for classes with property hooks)
+--FILE--
+<?php
+
+class ClassWithPropertyHooks
+{
+    public string $name {
+        get => 'virtual';
+    }
+}
+
+class IterableClassWithPropertyHooks implements IteratorAggregate
+{
+    public string $name {
+        get => 'virtual';
+    }
+
+    public function getIterator(): Traversable
+    {
+        return new ArrayIterator([]);
+    }
+}
+
+$classes = [
+    'ClassWithPropertyHooks' => false,
+    'IterableClassWithPropertyHooks' => true,
+];
+
+foreach ($classes as $className => $expected) {
+    $status = (new ReflectionClass($className)->isIterable() === $expected) ? 'PASS' : 'FAIL';
+    echo "$className: $status\n";
+}
+
+?>
+--EXPECT--
+ClassWithPropertyHooks: PASS
+IterableClassWithPropertyHooks: PASS