diff --git a/src/http/v3/ngx_http_v3.c b/src/http/v3/ngx_http_v3.c
index cca84dbc1..f7f79b9f4 100644
--- a/src/http/v3/ngx_http_v3.c
+++ b/src/http/v3/ngx_http_v3.c
@@ -34,21 +34,25 @@ ngx_http_v3_encode_varlen_int(u_char *p, uint64_t value)
 
     if (value <= 1073741823) {
         if (p == NULL) {
-            return 3;
+            return 4;
         }
 
-        *p++ = 0x80 | (value >> 16);
+        *p++ = 0x80 | (value >> 24);
+        *p++ = (value >> 16);
         *p++ = (value >> 8);
         *p++ = value;
         return (uintptr_t) p;
-
     }
 
     if (p == NULL) {
-        return 4;
+        return 8;
     }
 
-    *p++ = 0xc0 | (value >> 24);
+    *p++ = 0xc0 | (value >> 56);
+    *p++ = (value >> 48);
+    *p++ = (value >> 40);
+    *p++ = (value >> 32);
+    *p++ = (value >> 24);
     *p++ = (value >> 16);
     *p++ = (value >> 8);
     *p++ = value;