--- JSON-XS/XS.xs	2007/07/01 23:40:07	1.49
+++ JSON-XS/XS.xs	2007/07/02 00:29:38	1.50
@@ -526,9 +526,12 @@
     encode_av (enc, (AV *)sv);
   else if (svt < SVt_PVAV)
     {
-      if (SvNIOK (sv) && SvIV (sv) == 0)
+      STRLEN len = 0;
+      char *pv = svt ? SvPV (sv, len) : 0;
+
+      if (len == 1 && *pv == '0')
         encode_str (enc, "false", 5, 0);
-      else if (SvNIOK (sv) && SvIV (sv) == 1)
+      else if (len == 1 && *pv == '1')
         encode_str (enc, "true", 4, 0);
       else
         croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",