diff --git a/python/brotlimodule.cc b/python/brotlimodule.cc
index 351e133..7994713 100644
--- a/python/brotlimodule.cc
+++ b/python/brotlimodule.cc
@@ -20,6 +20,7 @@ static int as_uint8(PyObject *o, int* result) {
     return 0;
   }
   *result = (int) value;
+  return 1;
 }
 
 static int mode_convertor(PyObject *o, BrotliParams::Mode *mode) {