diff --git a/README b/README
index 647df05..0953f37 100644
--- a/README
+++ b/README
@@ -102,10 +102,14 @@
 
         ./configure CXXFLAGS='-g -O2'
         ./configure CFLAGS='-g -O2'
-        ./configure CPPFLAGS='-g -O2'
+        ./configure CPPFLAGS='-DDEBUG_MY_FEATURE'
 
 Run ./configure --help to see other configuration options
 
+Please be aware that the Python library will ignore the --prefix option
+and just install wherever Python's distutils puts it (usually along
+the lines of /usr/lib/pythonX.Y/site-packages/).  DESTDIR is respected.
+
 Make thrift:
 
 	make