--- a/src/cbf_ws.c	2021-01-26 15:31:04.793960741 +0900
+++ b/src/cbf_ws.c	2021-01-26 15:32:08.092795581 +0900
@@ -1034,7 +1034,7 @@
         
         const char * line;
         
-        char c, cprev, cprevprev, cprevprevprev;
+        int c, cprev, cprevprev, cprevprevprev;
         
         size_t length;