diff --git a/Doc/ext/newtypes.tex b/Doc/ext/newtypes.tex
index 3948993..cfc76b8 100644
--- a/Doc/ext/newtypes.tex
+++ b/Doc/ext/newtypes.tex
@@ -749,7 +749,7 @@
 newdatatype_dealloc(newdatatypeobject * obj)
 {
     free(obj->obj_UnderlyingDatatypePtr);
-    obj->ob_type->tp_free(self);
+    obj->ob_type->tp_free(obj);
 }
 \end{verbatim}