diff --git a/DESCRIPTION b/DESCRIPTION
index d88ce21..60dfe72 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: otndo
 Title: Understand your OTN data
-Version: 0.3.0
+Version: 0.3.1
 Authors@R: 
     person("Michael", "O'Brien", , "mike@obrien.page", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0003-1420-6395"))
diff --git a/R/utilities_make.R b/R/utilities_make.R
index 6806a79..53bfd0c 100644
--- a/R/utilities_make.R
+++ b/R/utilities_make.R
@@ -156,7 +156,7 @@ write_to_tempdir <- function(type, files, temp_dir) {
 
   ##  Write file to temporary directory
   filepath <- file.path(temp_dir, paste0(type, ".csv"))
-  write.csv(files, filepath,
+  data.table::fwrite(files, filepath,
     row.names = F
   )
 
diff --git a/tests/testthat/test-write_to_tempdir.R b/tests/testthat/test-write_to_tempdir.R
index ea3f2aa..7612eb3 100644
--- a/tests/testthat/test-write_to_tempdir.R
+++ b/tests/testthat/test-write_to_tempdir.R
@@ -1,7 +1,45 @@
 test_that("writes and converts deployment data", {
-  skip("Test TBD")
+  deployment_filepath <- write_to_tempdir(
+    type = "deployment",
+    files = pbsm$deployment,
+    temp_dir = td
+  )
+
+  expect_true(file.exists(deployment_filepath))
+
+
+  deployment <- data.table::fread(deployment_filepath)
+
+  expect_named(
+    deployment,
+    c(
+      "stationname", "receiver", "internal_transmitter", "deploy_date_time",
+      "deploy_lat", "deploy_long", "recover_date_time"
+    )
+  )
+
+  expect_s3_class(
+    deployment$deploy_date_time,
+    "POSIXct"
+  )
+  expect_s3_class(
+    deployment$recover_date_time,
+    "POSIXct"
+  )
+
+  expect_type(
+    deployment$deploy_lat,
+    "double"
+  )
+
+  expect_type(
+    deployment$deploy_lon,
+    "double"
+  )
+
 })
 
+
 test_that("works with multiple deployment files", {
   skip("Test TBD")
 })