diff --git a/panda/src/event/asyncFuture_ext.cxx b/panda/src/event/asyncFuture_ext.cxx
index 0ac681f1b2..c181085280 100644
--- a/panda/src/event/asyncFuture_ext.cxx
+++ b/panda/src/event/asyncFuture_ext.cxx
@@ -332,8 +332,7 @@ add_done_callback(PyObject *self, PyObject *fn) {
   }
 
   PythonTask *task = new PythonTask(fn);
-  Py_DECREF(task->_args);
-  task->_args = PyTuple_Pack(1, self);
+  task->_args.assign(1, Py_NewRef(self));
   task->_append_task = false;
   task->_ignore_return = true;
 
diff --git a/panda/src/event/pythonTask.cxx b/panda/src/event/pythonTask.cxx
index bc540a75ac..264442d27e 100644
--- a/panda/src/event/pythonTask.cxx
+++ b/panda/src/event/pythonTask.cxx
@@ -37,7 +37,6 @@ PythonTask::
 PythonTask(PyObject *func_or_coro, const std::string &name) :
   AsyncTask(name),
   _function(nullptr),
-  _args(nullptr),
   _upon_death(nullptr),
   _owner(nullptr),
   _exception(nullptr),
@@ -45,6 +44,7 @@ PythonTask(PyObject *func_or_coro, const std::string &name) :
   _exc_traceback(nullptr),
   _generator(nullptr),
   _fut_waiter(nullptr),
+  _append_task(true),
   _ignore_return(false),
   _registered_to_owner(false),
   _retrieved_exception(false) {
@@ -63,7 +63,6 @@ PythonTask(PyObject *func_or_coro, const std::string &name) :
     nassert_raise("Invalid function passed to PythonTask");
   }
 
-  set_args(Py_None, true);
   set_upon_death(Py_None);
   set_owner(Py_None);
 
@@ -104,7 +103,9 @@ PythonTask::
 
   // All of these may have already been cleared by __clear__.
   Py_XDECREF(_function);
-  Py_XDECREF(_args);
+  for (PyObject *arg : _args) {
+    Py_DECREF(arg);
+  }
   Py_XDECREF(__dict__);
   Py_XDECREF(_exception);
   Py_XDECREF(_exc_value);
@@ -134,21 +135,23 @@ set_function(PyObject *function) {
  */
 void PythonTask::
 set_args(PyObject *args, bool append_task) {
-  Py_XDECREF(_args);
-  _args = nullptr;
+  pvector<PyObject *> old_args = std::exchange(_args, {});
 
-  if (args == Py_None) {
-    // None means no arguments; create an empty tuple.
-    _args = PyTuple_New(0);
-  } else {
-    if (PySequence_Check(args)) {
-      _args = PySequence_Tuple(args);
+  if (PySequence_Check(args)) {
+    Py_ssize_t len = PySequence_Size(args);
+    _args.resize(len);
+
+    for (Py_ssize_t i = 0; i < len; ++i) {
+      _args[i] = PySequence_GetItem(args, i);
     }
   }
-
-  if (_args == nullptr) {
+  else if (args != Py_None) {
     nassert_raise("Invalid args passed to PythonTask");
-    _args = PyTuple_New(0);
+    return;
+  }
+
+  for (PyObject *old_arg : old_args) {
+    Py_DECREF(old_arg);
   }
 
   _append_task = append_task;
@@ -159,19 +162,18 @@ set_args(PyObject *args, bool append_task) {
  */
 PyObject *PythonTask::
 get_args() {
+  // If we want to append the task, we have to create a new tuple with space
+  // for one more at the end.  We have to do this dynamically each time, to
+  // avoid storing the task itself in its own arguments list, and thereby
+  // creating a cyclical reference.
+
+  size_t num_args = _args.size();
+  PyObject *result = PyTuple_New(num_args + _append_task);
+  for (size_t i = 0; i < num_args; ++i) {
+    PyTuple_SET_ITEM(result, i, Py_NewRef(_args[i]));
+  }
+
   if (_append_task) {
-    // If we want to append the task, we have to create a new tuple with space
-    // for one more at the end.  We have to do this dynamically each time, to
-    // avoid storing the task itself in its own arguments list, and thereby
-    // creating a cyclical reference.
-
-    int num_args = PyTuple_GET_SIZE(_args);
-    PyObject *with_task = PyTuple_New(num_args + 1);
-    for (int i = 0; i < num_args; ++i) {
-      PyObject *item = PyTuple_GET_ITEM(_args, i);
-      PyTuple_SET_ITEM(with_task, i, Py_NewRef(item));
-    }
-
     // Check whether we have a Python wrapper.  This is not the case if the
     // object has been created by C++ and never been exposed to Python code.
     if (__self__ == nullptr) {
@@ -180,12 +182,9 @@ get_args() {
       __self__ = DTool_CreatePyInstance(this, Dtool_PythonTask, true, false);
     }
 
-    PyTuple_SET_ITEM(with_task, num_args, Py_NewRef(__self__));
-    return with_task;
-  }
-  else {
-    return Py_NewRef(_args);
+    PyTuple_SET_ITEM(result, num_args, Py_NewRef(__self__));
   }
+  return result;
 }
 
 /**
@@ -376,7 +375,9 @@ int PythonTask::
 __traverse__(visitproc visit, void *arg) {
   Py_VISIT(__self__);
   Py_VISIT(_function);
-  Py_VISIT(_args);
+  for (PyObject *arg : _args) {
+    Py_VISIT(arg);
+  }
   Py_VISIT(_upon_death);
   Py_VISIT(_owner);
   Py_VISIT(__dict__);
@@ -390,7 +391,12 @@ __traverse__(visitproc visit, void *arg) {
 int PythonTask::
 __clear__() {
   Py_CLEAR(_function);
-  Py_CLEAR(_args);
+  {
+    pvector<PyObject *> old_args = std::exchange(_args, {});
+    for (PyObject *arg : old_args) {
+      Py_DECREF(arg);
+    }
+  }
   Py_CLEAR(_upon_death);
   Py_CLEAR(_owner);
   Py_CLEAR(__dict__);
@@ -590,9 +596,21 @@ do_python_task() {
     // We are calling the function directly.
     nassertr(_function != nullptr, DS_interrupt);
 
-    PyObject *args = get_args();
-    result = PythonThread::call_python_func(_function, args);
-    Py_DECREF(args);
+    size_t nargs = _args.size();
+    PyObject **args = (PyObject **)alloca(sizeof(PyObject *) * (nargs + 2)) + 1;
+    std::copy(_args.begin(), _args.end(), args);
+
+    if (_append_task) {
+      // Check whether we have a Python wrapper.  This is not the case if the
+      // object has been created by C++ and never been exposed to Python code.
+      if (__self__ == nullptr) {
+        // A __self__ instance does not exist, let's create one now.
+        ref();
+        __self__ = DTool_CreatePyInstance(this, Dtool_PythonTask, true, false);
+      }
+      args[nargs++] = __self__;
+    }
+    result = PythonThread::call_python_func(_function, args, nargs | PY_VECTORCALL_ARGUMENTS_OFFSET);
 
     if (result != nullptr && PyGen_Check(result)) {
       // The function has yielded a generator.  We will call into that
diff --git a/panda/src/event/pythonTask.h b/panda/src/event/pythonTask.h
index 148252e999..67ae3ed17a 100644
--- a/panda/src/event/pythonTask.h
+++ b/panda/src/event/pythonTask.h
@@ -114,7 +114,7 @@ private:
 
 private:
   PyObject *_function;
-  PyObject *_args;
+  pvector<PyObject *> _args;
   PyObject *_upon_death;
   PyObject *_owner;
 
diff --git a/panda/src/gobj/pythonTexturePoolFilter.cxx b/panda/src/gobj/pythonTexturePoolFilter.cxx
index 0fc11b181d..f20cc094ce 100644
--- a/panda/src/gobj/pythonTexturePoolFilter.cxx
+++ b/panda/src/gobj/pythonTexturePoolFilter.cxx
@@ -101,17 +101,19 @@ pre_load(const Filename &orig_filename, const Filename &orig_alpha_filename,
 #endif
 
   // Wrap the arguments.
-  PyObject *args = Py_BuildValue("(OOiiNO)",
-    DTool_CreatePyInstance((void *)&orig_filename, Dtool_Filename, false, true),
-    DTool_CreatePyInstance((void *)&orig_alpha_filename, Dtool_Filename, false, true),
-    primary_file_num_channels,
-    alpha_file_channel,
-    PyBool_FromLong(read_mipmaps),
-    DTool_CreatePyInstance((void *)&options, Dtool_LoaderOptions, false, true)
-  );
+  PyObject *args[7];
+  args[1] = DTool_CreatePyInstance((void *)&orig_filename, Dtool_Filename, false, true);
+  args[2] = DTool_CreatePyInstance((void *)&orig_alpha_filename, Dtool_Filename, false, true);
+  args[3] = PyLong_FromLong(primary_file_num_channels);
+  args[4] = PyLong_FromLong(alpha_file_channel);
+  args[5] = PyBool_FromLong(read_mipmaps);
+  args[6] = DTool_CreatePyInstance((void *)&options, Dtool_LoaderOptions, false, true);
 
-  PyObject *result = PythonThread::call_python_func(_pre_load_func, args);
-  Py_DECREF(args);
+  PyObject *result = PythonThread::call_python_func(_pre_load_func, args + 1, 6 | PY_VECTORCALL_ARGUMENTS_OFFSET);
+
+  for (size_t i = 1; i < 7; ++i) {
+    Py_DECREF(args[i]);
+  }
 
   PT(Texture) tex;
   if (result != nullptr) {
@@ -162,11 +164,11 @@ post_load(Texture *tex) {
 #endif
 
   // Wrap the arguments.
-  PyObject *args = PyTuple_Pack(1,
-    DTool_CreatePyInstance(tex, Dtool_Texture, true, false)
-  );
-  PyObject *result = PythonThread::call_python_func(_post_load_func, args);
-  Py_DECREF(args);
+  PyObject *args[2];
+  args[1] = DTool_CreatePyInstance(tex, Dtool_Texture, true, false);
+
+  PyObject *result = PythonThread::call_python_func(_post_load_func, args + 1, 1 | PY_VECTORCALL_ARGUMENTS_OFFSET);
+  Py_DECREF(args[1]);
 
   PT(Texture) result_tex;
   if (result != nullptr) {
diff --git a/panda/src/pgraph/pythonLoaderFileType.cxx b/panda/src/pgraph/pythonLoaderFileType.cxx
index aa4b84cceb..b33930cffe 100644
--- a/panda/src/pgraph/pythonLoaderFileType.cxx
+++ b/panda/src/pgraph/pythonLoaderFileType.cxx
@@ -305,19 +305,19 @@ load_file(const Filename &path, const LoaderOptions &options,
 #endif
 
   // Wrap the arguments.
-  PyObject *args = PyTuple_New(3);
-  PyTuple_SET_ITEM(args, 0, DTool_CreatePyInstance((void *)&path, Dtool_Filename, false, true));
-  PyTuple_SET_ITEM(args, 1, DTool_CreatePyInstance((void *)&options, Dtool_LoaderOptions, false, true));
+  PyObject *args[4];
+  args[1] = DTool_CreatePyInstance((void *)&path, Dtool_Filename, false, true);
+  args[2] = DTool_CreatePyInstance((void *)&options, Dtool_LoaderOptions, false, true);
   if (record != nullptr) {
     record->ref();
-    PyTuple_SET_ITEM(args, 2, DTool_CreatePyInstanceTyped((void *)record, Dtool_BamCacheRecord, true, false, record->get_type_index()));
+    args[3] = DTool_CreatePyInstanceTyped((void *)record, Dtool_BamCacheRecord, true, false, record->get_type_index());
   } else {
-    PyTuple_SET_ITEM(args, 2, Py_NewRef(Py_None));
+    args[3] = Py_NewRef(Py_None);
   }
 
   PT(PandaNode) node;
 
-  PyObject *result = PythonThread::call_python_func(_load_func, args);
+  PyObject *result = PythonThread::call_python_func(_load_func, args + 1, 3 | PY_VECTORCALL_ARGUMENTS_OFFSET);
   if (result != nullptr) {
     if (DtoolInstance_Check(result)) {
       node = (PandaNode *)DtoolInstance_UPCAST(result, Dtool_PandaNode);
@@ -325,7 +325,9 @@ load_file(const Filename &path, const LoaderOptions &options,
     Py_DECREF(result);
   }
 
-  Py_DECREF(args);
+  Py_DECREF(args[1]);
+  Py_DECREF(args[2]);
+  Py_DECREF(args[3]);
 
   if (node == nullptr) {
     PyObject *exc_type = PyErr_Occurred();
@@ -372,13 +374,16 @@ save_file(const Filename &path, const LoaderOptions &options,
 #endif
 
   // Wrap the arguments.
-  PyObject *args = PyTuple_New(3);
-  PyTuple_SET_ITEM(args, 0, DTool_CreatePyInstance((void *)&path, Dtool_Filename, false, true));
-  PyTuple_SET_ITEM(args, 1, DTool_CreatePyInstance((void *)&options, Dtool_LoaderOptions, false, true));
-  PyTuple_SET_ITEM(args, 2, DTool_CreatePyInstanceTyped((void *)node, Dtool_PandaNode, true, false, node->get_type_index()));
+  PyObject *args[4];
+  args[1] = DTool_CreatePyInstance((void *)&path, Dtool_Filename, false, true);
+  args[2] = DTool_CreatePyInstance((void *)&options, Dtool_LoaderOptions, false, true);
+  args[3] = DTool_CreatePyInstanceTyped((void *)node, Dtool_PandaNode, true, false, node->get_type_index());
+
+  PyObject *result = PythonThread::call_python_func(_save_func, args + 1, 3 | PY_VECTORCALL_ARGUMENTS_OFFSET);
+  Py_DECREF(args[1]);
+  Py_DECREF(args[2]);
+  Py_DECREF(args[3]);
 
-  PyObject *result = PythonThread::call_python_func(_load_func, args);
-  Py_DECREF(args);
   if (result != nullptr) {
     Py_DECREF(result);
   } else {
diff --git a/panda/src/pipeline/pythonThread.cxx b/panda/src/pipeline/pythonThread.cxx
index 84770c258e..eff5728aaf 100644
--- a/panda/src/pipeline/pythonThread.cxx
+++ b/panda/src/pipeline/pythonThread.cxx
@@ -123,7 +123,7 @@ set_args(PyObject *args) {
  * exception.
  */
 PyObject *PythonThread::
-call_python_func(PyObject *function, PyObject *args) {
+call_python_func(PyObject *function, PyObject **args, size_t nargsf) {
   Thread *current_thread = get_current_thread();
 
   // Create a new Python thread state data structure, so Python can properly
@@ -132,7 +132,7 @@ call_python_func(PyObject *function, PyObject *args) {
 
   if (current_thread == get_main_thread()) {
     // In the main thread, just call the function.
-    result = PyObject_Call(function, args, nullptr);
+    result = _PyObject_Vectorcall(function, args, nargsf, nullptr);
 
     if (result == nullptr) {
       if (PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_SystemExit)) {
@@ -189,7 +189,7 @@ call_python_func(PyObject *function, PyObject *args) {
     PyThreadState_Swap(new_thread_state);
 
     // Call the user's function.
-    result = PyObject_Call(function, args, nullptr);
+    result = _PyObject_Vectorcall(function, args, nargsf, nullptr);
     if (result == nullptr && PyErr_Occurred()) {
       // We got an exception.  Move the exception from the current thread into
       // the main thread, so it can be handled there.
@@ -230,7 +230,7 @@ call_python_func(PyObject *function, PyObject *args) {
     gstate = PyGILState_Ensure();
 
     // Call the user's function.
-    result = PyObject_Call(function, args, nullptr);
+    result = _PyObject_Vectorcall(function, args, nargsf, nullptr);
     if (result == nullptr && PyErr_Occurred()) {
       // We got an exception.  Move the exception from the current thread into
       // the main thread, so it can be handled there.
@@ -275,7 +275,9 @@ call_python_func(PyObject *function, PyObject *args) {
  */
 void PythonThread::
 thread_main() {
-  _result = call_python_func(_function, _args);
+  PyObject **args = &PyTuple_GET_ITEM(_args, 0);
+  Py_ssize_t nargs = PyTuple_GET_SIZE(_args);
+  _result = call_python_func(_function, args, (size_t)nargs);
 }
 
 #endif  // HAVE_PYTHON
diff --git a/panda/src/pipeline/pythonThread.h b/panda/src/pipeline/pythonThread.h
index eb57351149..f9bf6c91e9 100644
--- a/panda/src/pipeline/pythonThread.h
+++ b/panda/src/pipeline/pythonThread.h
@@ -36,7 +36,8 @@ public:
   PyObject *get_args() const;
   void set_args(PyObject *);
 
-  static PyObject *call_python_func(PyObject *function, PyObject *args);
+  static PyObject *call_python_func(PyObject *function, PyObject **args,
+                                    size_t nargsf);
 
 PUBLISHED:
   MAKE_PROPERTY(args, get_args, set_args);
diff --git a/panda/src/putil/bamReader_ext.cxx b/panda/src/putil/bamReader_ext.cxx
index 84c5060e1e..e85606b440 100644
--- a/panda/src/putil/bamReader_ext.cxx
+++ b/panda/src/putil/bamReader_ext.cxx
@@ -41,15 +41,14 @@ static TypedWritable *factory_callback(const FactoryParams &params){
   BamReader *manager;
   parse_params(params, scan, manager);
 
-  PyObject *py_scan = DTool_CreatePyInstance(&scan, Dtool_DatagramIterator, false, false);
-  PyObject *py_manager = DTool_CreatePyInstance(manager, Dtool_BamReader, false, false);
-  PyObject *args = PyTuple_Pack(2, py_scan, py_manager);
+  PyObject *args[3];
+  args[1] = DTool_CreatePyInstance(&scan, Dtool_DatagramIterator, false, false);
+  args[2] = DTool_CreatePyInstance(manager, Dtool_BamReader, false, false);
 
   // Now call the Python function.
-  PyObject *result = PythonThread::call_python_func(func, args);
-  Py_DECREF(args);
-  Py_DECREF(py_scan);
-  Py_DECREF(py_manager);
+  PyObject *result = PythonThread::call_python_func(func, args + 1, 2 | PY_VECTORCALL_ARGUMENTS_OFFSET);
+  Py_DECREF(args[1]);
+  Py_DECREF(args[2]);
 
   if (result == nullptr) {
     util_cat.error()
diff --git a/panda/src/putil/pythonCallbackObject.cxx b/panda/src/putil/pythonCallbackObject.cxx
index 4fc2da8173..8607273a6a 100644
--- a/panda/src/putil/pythonCallbackObject.cxx
+++ b/panda/src/putil/pythonCallbackObject.cxx
@@ -129,16 +129,13 @@ void PythonCallbackObject::
 do_python_callback(CallbackData *cbdata) {
   nassertv(cbdata != nullptr);
 
-  // Wrap the cbdata up in a Python object, then put it in a tuple, for the
-  // argument list.
-  PyObject *pycbdata =
-    DTool_CreatePyInstanceTyped(cbdata, Dtool_TypedObject,
-                                false, false, cbdata->get_type_index());
-  PyObject *args = Py_BuildValue("(O)", pycbdata);
-  Py_DECREF(pycbdata);
+  // Wrap the cbdata up in a Python object.
+  PyObject *args[2];
+  args[1] = DTool_CreatePyInstanceTyped(cbdata, Dtool_TypedObject,
+                                        false, false, cbdata->get_type_index());
 
-  PyObject *result = PythonThread::call_python_func(_function, args);
-  Py_DECREF(args);
+  PyObject *result = PythonThread::call_python_func(_function, args + 1, 1 | PY_VECTORCALL_ARGUMENTS_OFFSET);
+  Py_DECREF(args[1]);
 
   if (result == nullptr) {
     if (PyErr_Occurred() != PyExc_SystemExit) {