diff --git a/pb.c b/pb.c
index b65c5e2..f57ed89 100755
--- a/pb.c
+++ b/pb.c
@@ -340,7 +340,7 @@ static uint64_t lpb_tointegerx(lua_State *L, int idx, int *isint) {
     } else {
         for (; *s != '\0'; ++s) {
             int n = lpb_hexchar(*s);
-            if (n < 0 || n > 10) break;
+            if (n < 0 || n > 9) break;
             v = v * 10 + n;
         }
     }