diff --git a/src/http/ngx_http_parse.c b/src/http/ngx_http_parse.c
index e1328da04..e547d0fdb 100644
--- a/src/http/ngx_http_parse.c
+++ b/src/http/ngx_http_parse.c
@@ -2420,7 +2420,7 @@ data:
     ctx->state = state;
     b->pos = pos;
 
-    if (ctx->size > NGX_MAX_OFF_T_VALUE - 5) {
+    if (ctx->size > NGX_MAX_OFF_T_VALUE - 9) {
         goto invalid;
     }