--- a/setup.py	2013-03-19 07:30:25.000000000 -0400
+++ b/setup.py	2013-06-06 18:02:03.542285031 -0400
@@ -13,2 +13,9 @@ def find_packages(toplevel):
 
+modules  = [
+      Extension(name = "sipsimple.core._core",
+      sources = ["sipsimple/core/_core.pyx", "sipsimple/core/_core.pxd"] + glob.glob(os.path.join("sipsimple", "core", "_core.*.pxi")))
+      ]
+for e in modules:
+    e.cython_directives = {'c_string_encoding': 'ascii'}
+
 setup(name         = "python-sipsimple",
@@ -32,6 +39,3 @@ setup(name         = "python-sipsimple",
       },
-      ext_modules  = [
-            Extension(name = "sipsimple.core._core",
-            sources = ["sipsimple/core/_core.pyx", "sipsimple/core/_core.pxd"] + glob.glob(os.path.join("sipsimple", "core", "_core.*.pxi")))
-            ],
+      ext_modules = modules,
       cmdclass = {