diff --git a/src/http/v2/ngx_http_v2_filter_module.c b/src/http/v2/ngx_http_v2_filter_module.c
index 2d1ced6..a866cde 100644
--- a/src/http/v2/ngx_http_v2_filter_module.c
+++ b/src/http/v2/ngx_http_v2_filter_module.c
@@ -12,7 +12,12 @@
 #include <ngx_http_v2_module.h>
 
 
-#define ngx_http_v2_integer_octets(v)  (((v) + 127) / 128)
+/*
+ * This returns precise number of octets for values in range 0..253
+ * and estimate number for the rest, but not smaller than required.
+ */
+
+#define ngx_http_v2_integer_octets(v)  (1 + (v) / 127)
 
 #define ngx_http_v2_literal_size(h)                                           \
     (ngx_http_v2_integer_octets(sizeof(h) - 1) + sizeof(h) - 1)