diff --git a/3rd/box2d/src/box2d_Body.cpp b/3rd/box2d/src/box2d_Body.cpp
index e6fa0830..ea1df5eb 100644
--- a/3rd/box2d/src/box2d_Body.cpp
+++ b/3rd/box2d/src/box2d_Body.cpp
@@ -108,7 +108,7 @@ void PyBody::_register(VM* vm, PyObject* mod, PyObject* type){
 
     // get_node
     vm->bind(type, "get_node(self)", [](VM* vm, ArgsView args){
-        PyBody& body = CAST(PyBody&, args[1]);
+        PyBody& body = CAST(PyBody&, args[0]);
         return body.node_like;
     });