diff --git a/src/PYConfig.cc b/src/PYConfig.cc
index 7e24b2c..1ef0b99 100644
--- src/PYConfig.cc
+++ src/PYConfig.cc
@@ -114,6 +114,7 @@ Config::initDefaultValues (void)
     m_init_full_punct = TRUE;
     m_init_simp_chinese = TRUE;
     m_special_phrases = TRUE;
+    m_double_pinyin = FALSE;
     updateContext (PyZy::InputContext::PROPERTY_SPECIAL_PHRASE,
                    PyZy::Variant::fromBool (m_special_phrases));
 }