diff --git a/dev/flat_dock_from_renv.Rmd b/dev/flat_dock_from_renv.Rmd
index 62de8fd..bddb9ac 100644
--- a/dev/flat_dock_from_renv.Rmd
+++ b/dev/flat_dock_from_renv.Rmd
@@ -35,12 +35,11 @@ renv::snapshot(
   prompt = FALSE)
 
 # Create Dockerfile
-dock_from_renv(lockfile = the_lockfile,
+my_dock <- dock_from_renv(lockfile = the_lockfile,
                distro = "focal", 
-               FROM = "rstudio/verse",
-               out_dir = dir_build
+               FROM = "rstudio/verse"
               )
-
+my_dock$write(file.path(dir_build, "Dockerfile"))
 # rstudioapi::navigateToFile(file.path(dir_build, "Dockerfile"))
 unlink(dir_build)
 ```
@@ -71,28 +70,31 @@ writeLines(renv_file, file.path(dir_build, "renv.lock"))
 
 # dock_from_renv ----
 test_that("dock_from_renv works", {
-  skip_if_not(interactive())
+  # skip_if_not(interactive())
   # Create Dockerfile
-  expect_error(
-    dock_from_renv(lockfile = the_lockfile,
+
+  out <-   dock_from_renv(lockfile = the_lockfile,
                    distro = "focal",
                    FROM = "rocker/verse",
-                   out_dir = dir_build
-    ), regexp = NA)
-
+    )
+  expect_s3_class(out,"Dockerfile")
+  expect_s3_class(out,"R6")
   # read Dockerfile
+  out$write(file.path(dir_build, "Dockerfile"))
   dock_created <- readLines(file.path(dir_build, "Dockerfile"))
-  expect_equal(
-    dock_created[grep("renv.lock.dock renv.lock", dock_created)],
-    paste0("COPY ", dir_build, "/renv.lock.dock renv.lock")
+  expect_equal(dock_created[1], "FROM rocker/verse:4.1.2")
+
+  expect_length(
+        grep("install.packages\\(c\\(\"renv\",\"remotes\"", dock_created) , 1
+  )
+  expect_length(
+    grep("RUN R -e 'renv::restore\\(\\)'", dock_created), 1
   )
-  dock_created[grep("renv.lock.dock renv.lock", dock_created)] <-
-    "COPY renv.lock.dock renv.lock"
 
-  # file.copy(file.path(dir_build, "Dockerfile"), "inst/renv_Dockefile", overwrite = TRUE)
+  # System dependencies are different when build in interactive environment?
+  skip_if_not(interactive())
+  file.copy(file.path(dir_build, "Dockerfile"), "inst/renv_Dockefile", overwrite = TRUE)
   dock_expected <- readLines(system.file("renv_Dockefile", package = "dockerfiler"))
-  dock_expected[grep("renv.lock.dock renv.lock", dock_expected)] <-
-    "COPY renv.lock.dock renv.lock"
 
   expect_equal(dock_created, dock_expected)
 })
@@ -101,7 +103,7 @@ unlink(dir_build)
 
 # repos_as_character ----
 test_that("repos_as_character works", {
-  out <- repos_as_character(
+  out <- dockerfiler:::repos_as_character(
     repos = c(
       RSPM = paste0("https://packagemanager.rstudio.com/all/__linux__/focal/latest"),
       CRAN = "https://cran.rstudio.com/")
@@ -113,14 +115,14 @@ test_that("repos_as_character works", {
 
 # gen_base_image ----
 test_that("gen_base_image works", {
-  out <- gen_base_image(
+  out <- dockerfiler:::gen_base_image(
     distro = "focal",
     r_version = "4.0",
     FROM = "rstudio/r-base"
   )
   expect_equal(out, "rstudio/r-base:4.0-focal")
 
-  out <- gen_base_image(
+  out <- dockerfiler:::gen_base_image(
     distro = "focal",
     r_version = "4.0",
     FROM = "rocker/verse"
diff --git a/tests/testthat/test-dock_from_renv.R b/tests/testthat/test-dock_from_renv.R
index 9ec9c21..3d17266 100644
--- a/tests/testthat/test-dock_from_renv.R
+++ b/tests/testthat/test-dock_from_renv.R
@@ -1,3 +1,5 @@
+# WARNING - Generated by {fusen} from /dev/flat_dock_from_renv.Rmd: do not edit by hand
+
 dir_build <- tempfile(pattern = "renv")
 dir.create(dir_build)
 
@@ -82,3 +84,4 @@ test_that("gen_base_image works", {
   )
   expect_equal(out, "rocker/verse:4.0")
 })
+
diff --git a/vignettes/dockerfile-from-renv-lock.Rmd b/vignettes/dockerfile-from-renv-lock.Rmd
index 037845b..5151f43 100644
--- a/vignettes/dockerfile-from-renv-lock.Rmd
+++ b/vignettes/dockerfile-from-renv-lock.Rmd
@@ -18,7 +18,7 @@ knitr::opts_chunk$set(
 library(dockerfiler)
 ```
 
-<!-- This vignette is generated by fusen: do not edit by hand -->
+<!-- WARNING - This vignette is generated by {fusen} from /dev/flat_dock_from_renv.Rmd: do not edit by hand -->
 
 <!--
  You need to run the 'description' chunk in the '0-dev_history.Rmd' file before continuing your code there.
@@ -47,12 +47,11 @@ renv::snapshot(
   prompt = FALSE)
 
 # Create Dockerfile
-dock_from_renv(lockfile = the_lockfile,
+my_dock <- dock_from_renv(lockfile = the_lockfile,
                distro = "focal", 
-               FROM = "rstudio/verse",
-               out_dir = dir_build
+               FROM = "rstudio/verse"
               )
-
+my_dock$write(file.path(dir_build, "Dockerfile"))
 # rstudioapi::navigateToFile(file.path(dir_build, "Dockerfile"))
 unlink(dir_build)
 ```