--- JSON-XS/XS.xs	2009/09/08 18:00:03	1.101
+++ JSON-XS/XS.xs	2009/10/10 01:48:50	1.102
@@ -19,7 +19,8 @@
 # define UTF8_MAXBYTES 13
 #endif
 
-#define IVUV_MAXCHARS (sizeof (UV) * CHAR_BIT * 28 / 93 + 2)
+// three extra for rounding, sign, and end of string
+#define IVUV_MAXCHARS (sizeof (UV) * CHAR_BIT * 28 / 93 + 3)
 
 #define F_ASCII          0x00000001UL
 #define F_LATIN1         0x00000002UL