Index: pyzy-0.1.0/src/Types.h
===================================================================
--- pyzy-0.1.0.orig/src/Types.h
+++ pyzy-0.1.0/src/Types.h
@@ -26,7 +26,7 @@
 
 namespace PyZy {
 
-#define PINYIN_ID_VOID  (-1)
+#define PINYIN_ID_VOID  (char(-1))
 #define PINYIN_ID_ZERO  (0)
 #define PINYIN_ID_B     (1)
 #define PINYIN_ID_C     (2)