diff --git a/tools/cythonize.py b/tools/cythonize.py
index 10aaa8d..4e79136 100755
--- a/tools/cythonize.py
+++ b/tools/cythonize.py
@@ -22,12 +22,17 @@ def do(fn):
         fn_c = fn[:-3] + 'c'
         with open(fn_c) as fd:
             data = fd.read()
+        modname = modname.split('.')[-1]
         pat1 = 'init{}(void)'.format(modname)
         sub1 = 'init{}_{}(void)'.format(package, modname)
         pat2 = 'PyInit_{}(void)'.format(modname)
         sub2 = 'PyInit{}_{}(void)'.format(package, modname)
         pat3 = 'Pyx_NAMESTR("{}")'.format(modname)
         sub3 = 'Pyx_NAMESTR("{}_{}")'.format(package, modname)
+
+        print '1: {} -> {}'.format(pat1, sub1)
+        print '2: {} -> {}'.format(pat2, sub2)
+        print '3: {} -> {}'.format(pat3, sub3)
         data = data.replace(pat1, sub1)
         data = data.replace(pat2, sub2)
         data = data.replace(pat3, sub3)
@@ -37,5 +42,6 @@ def do(fn):
             fd.write(data)
 
 if __name__ == '__main__':
+    print '-- cythonize', sys.argv
     for fn in sys.argv[1:]:
         do(fn)