diff --git a/Zend/tests/attributes/deprecated/functions/gh17866.phpt b/Zend/tests/attributes/deprecated/functions/gh17866.phpt
new file mode 100644
index 00000000000..8786b49c602
--- /dev/null
+++ b/Zend/tests/attributes/deprecated/functions/gh17866.phpt
@@ -0,0 +1,35 @@
+--TEST--
+GH-17866 (zend_mm_heap corrupted error after upgrading from 8.4.3 to 8.4.4)
+--FILE--
+<?php
+
+class Foo {
+    #[Deprecated("xyzzy")]
+    public function __invoke() {
+        echo "In __invoke\n";
+    }
+}
+
+$foo = new Foo;
+$closure = Closure::fromCallable($foo);
+$test = $closure->__invoke(...);
+
+$rc = new ReflectionMethod($test, '__invoke');
+var_dump($rc->getAttributes());
+var_dump($rc->isDeprecated());
+
+$test();
+
+?>
+--EXPECTF--
+array(1) {
+  [0]=>
+  object(ReflectionAttribute)#%d (1) {
+    ["name"]=>
+    string(10) "Deprecated"
+  }
+}
+bool(true)
+
+Deprecated: Method Foo::__invoke() is deprecated, xyzzy in %s on line %d
+In __invoke
diff --git a/Zend/zend_closures.c b/Zend/zend_closures.c
index e7eb47a38bd..7b2621275dc 100644
--- a/Zend/zend_closures.c
+++ b/Zend/zend_closures.c
@@ -469,7 +469,7 @@ ZEND_API zend_function *zend_get_closure_invoke_method(zend_object *object) /* {
 	zend_closure *closure = (zend_closure *)object;
 	zend_function *invoke = (zend_function*)emalloc(sizeof(zend_function));
 	const uint32_t keep_flags =
-		ZEND_ACC_RETURN_REFERENCE | ZEND_ACC_VARIADIC | ZEND_ACC_HAS_RETURN_TYPE;
+		ZEND_ACC_RETURN_REFERENCE | ZEND_ACC_VARIADIC | ZEND_ACC_HAS_RETURN_TYPE | ZEND_ACC_DEPRECATED;
 
 	invoke->common = closure->func.common;
 	/* We return ZEND_INTERNAL_FUNCTION, but arg_info representation is the
diff --git a/Zend/zend_object_handlers.c b/Zend/zend_object_handlers.c
index b6d17a1149d..56bea759226 100644
--- a/Zend/zend_object_handlers.c
+++ b/Zend/zend_object_handlers.c
@@ -1618,12 +1618,8 @@ ZEND_API zend_function *zend_get_call_trampoline_func(const zend_class_entry *ce
 		| ZEND_ACC_PUBLIC
 		| ZEND_ACC_VARIADIC
 		| (fbc->common.fn_flags & (ZEND_ACC_RETURN_REFERENCE|ZEND_ACC_ABSTRACT|ZEND_ACC_DEPRECATED));
-	if (fbc->common.attributes) {
-		func->attributes = fbc->common.attributes;
-		GC_TRY_ADDREF(func->attributes);
-	} else {
-		func->attributes = NULL;
-	}
+	/* Attributes outlive the trampoline because they are created by the compiler. */
+	func->attributes = fbc->common.attributes;
 	if (is_static) {
 		func->fn_flags |= ZEND_ACC_STATIC;
 	}
diff --git a/Zend/zend_object_handlers.h b/Zend/zend_object_handlers.h
index 130e84b5c58..7e7d3df37a6 100644
--- a/Zend/zend_object_handlers.h
+++ b/Zend/zend_object_handlers.h
@@ -341,9 +341,6 @@ ZEND_API bool ZEND_FASTCALL zend_asymmetric_property_has_set_access(const zend_p
 } while (0)
 
 #define zend_free_trampoline(func) do { \
-		if ((func)->common.attributes) { \
-			zend_array_release((func)->common.attributes); \
-		} \
 		if ((func) == &EG(trampoline)) { \
 			EG(trampoline).common.attributes = NULL; \
 			EG(trampoline).common.function_name = NULL; \