consistent macro naming throughout the project
diff --git a/docs/classes.rst b/docs/classes.rst
index a7c75d8..db4dc42 100644
--- a/docs/classes.rst
+++ b/docs/classes.rst
@@ -27,7 +27,7 @@
 
     namespace py = pybind11;
 
-    PYBIND_PLUGIN(example) {
+    PYBIND11_PLUGIN(example) {
         py::module m("example", "pybind11 example plugin");
 
         py::class_<Pet>(m, "Pet")