diff --git a/DESCRIPTION b/DESCRIPTION
index 204d1b5..f1acc4a 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -2,7 +2,7 @@ Type: Package
 Package: slackr
 Title: Send Messages, Images, R Objects and Files to 'Slack'
     Channels/Users
-Version: 3.3.2
+Version: 3.4.0
 Authors@R: c(
     person("Matt", "Kaye", role = c("aut", "cre"), email = "mrkaye97@gmail.com", comment = c(website = "matthewrkaye.com")),
     person("Bob", "Rudis",role = c("aut")),
diff --git a/NEWS.md b/NEWS.md
index 3edbf5f..cefa241 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,7 @@
+# slackr 3.4.0
+
+* Fixes the internals of `files_upload` to use new Slack API and migrate off of [deprecated `files.upload` method](files.upload method)
+
 # slackr 3.3.1
 * Fixes a bug in `slackr_history` where the function fails to infer `posted_from_time` if not provided
 * Adds default `message_count = 100` to `slackr_history`
diff --git a/R/call_slack_internals.R b/R/call_slack_internals.R
index 19a5d62..7f292fd 100644
--- a/R/call_slack_internals.R
+++ b/R/call_slack_internals.R
@@ -112,19 +112,52 @@ files_upload <- function(
   token,
   ...
 ) {
-  r <- call_slack_api(
-    "/api/files.upload",
+  initial_upload_response <- call_slack_api(
+    "/api/files.getUploadURLExternal",
     .method = POST,
     token = token,
     body = list(
-      file = upload_file(file),
-      initial_comment = initial_comment,
-      channels = paste(channels, collapse = ","),
+      filename=file,
+      length=file.size(file)
+    )
+  )
+
+  initial_upload_content <- content(initial_upload_response)
+
+  upload_url <- initial_upload_content$upload_url
+  file_id <- initial_upload_content$file_id
+  channel <- slackr_chtrans(channels, token)
+
+  httr::POST(
+    url=upload_url,
+    body=upload_file(file)
+  )
+
+  kwargs <- list(...)
+  title <- kwargs$title
+
+  if (is.null(title)) {
+    inner <- list(id = file_id)
+  } else {
+    inner <- list(id = file_id, title = title)
+  }
+
+  response <- httr::POST(
+    "https://slack.com/api/files.completeUploadExternal",
+    add_headers(
+      .headers = c(Authorization = paste("Bearer", token))
+    ),
+    httr::content_type_json(),
+    encode="json",
+    body = list(
+      files = list(inner),
+      channel_id=channel,
+      initial_comment=initial_comment,
       ...
     )
   )
 
-  invisible(content(r))
+  invisible(content(response))
 }
 
 
diff --git a/logo.png b/logo.png
deleted file mode 100644
index 9367604..0000000
Binary files a/logo.png and /dev/null differ
diff --git a/tests/testthat/test-dev-tex.R b/tests/testthat/test-dev-tex.R
deleted file mode 100644
index b613f83..0000000
--- a/tests/testthat/test-dev-tex.R
+++ /dev/null
@@ -1,35 +0,0 @@
-test_that("slackr_dev posts", {
-  skip_on_cran()
-  skip_on_ci()
-
-  hist(rnorm(100))
-
-  post <- slackr_dev()
-
-  expect_true(post$ok)
-  expect_equal(post$file$filetype, "png")
-})
-
-test_that("slackr_tex posts with no dir specified", {
-  skip_on_cran()
-  skip_on_ci()
-
-  ## No path specified
-  post <- slackr_tex("$$e^{i \\pi} + 1 = 0$$")
-
-  expect_true(post$ok)
-  expect_equal(post$file$filetype, "png")
-})
-
-test_that("slackr_tex posts with dir specified", {
-  skip_on_cran()
-  skip_on_ci()
-
-  ## With path specified
-  d <- tempdir()
-  post <- slackr_tex("$$e^{i \\pi} + 1 = 0$$", path = d)
-
-  unlink(d, recursive = TRUE)
-  expect_true(post$ok)
-  expect_equal(post$file$filetype, "png")
-})
diff --git a/tests/testthat/test-history.R b/tests/testthat/test-history.R
index 2a5a7e3..82267ba 100644
--- a/tests/testthat/test-history.R
+++ b/tests/testthat/test-history.R
@@ -19,169 +19,3 @@ test_that("slackr_history correctly retrieves post", {
   )
 })
 
-test_that("slackr_history works when posted_from and posted_to are specified", {
-  skip_on_cran()
-
-  lapply(
-    c(TRUE, FALSE),
-    function(paginate) {
-      post <- slackr_msg("History posted_from posted_to test")
-
-      history <- slackr_history(
-        message_count = 1,
-        posted_from_time = post$ts,
-        posted_to_time = post$ts,
-        paginate = paginate
-      )
-
-      expect_identical(post$message$text, history$text)
-      expect_identical(post$message$subtype, history$subtype)
-      expect_identical(post$message$ts, history$ts)
-      expect_identical(post$message$bot_id, history$bot_id)
-      expect_identical(post$message$app_id, history$app_id)
-    }
-  )
-})
-
-test_that("slackr_history works with duration specified", {
-  skip_on_ci()
-  skip_on_cran()
-
-  post1 <- slackr_msg("History test post 1.")
-
-  Sys.sleep(5)
-
-  post2 <- slackr_msg("History test post 2.")
-
-  Sys.sleep(1.50)
-  to_ts <- as.numeric(Sys.time())
-
-  ## Check the past seven seconds
-  dur_s <- 7
-  dur_ms <- dur_s * 1000
-  dur_hours <- dur_s / 3600
-
-  history <- slackr_history(
-    message_count = 1000,
-    posted_to_time = to_ts,
-    duration = dur_hours
-  )
-
-  expect_gte(nrow(history), 2)
-  expect_gte(min(as.numeric(history$ts)), to_ts - dur_ms)
-
-  history_limited <- slackr_history(
-    message_count = 1000,
-    posted_to_time = to_ts,
-    duration = dur_hours / 2
-  )
-
-  expect_gte(as.numeric(post2$ts), max(as.numeric(history_limited$ts)))
-  expect_gte(nrow(history_limited), 1)
-})
-
-test_that("slackr_history works when posted_from and posted_to are specified for multiple posts", {
-  skip_on_cran()
-
-  lapply(
-    c(TRUE, FALSE),
-    function(paginate) {
-      post1 <- slackr_msg("History test post 1.")
-
-      Sys.sleep(1)
-
-      post2 <- slackr_msg("History test post 2.")
-      post3 <- slackr_csv(iris, initial_comment = "History test post 3.")
-      post4 <- slackr_msg("History test post 4.")
-
-      all_history <- slackr_history(
-        message_count = 1000,
-        posted_from_time = post1$ts,
-        posted_to_time = post4$ts,
-        paginate = paginate
-      )
-
-      expect_gte(nrow(all_history), 4)
-      expect_gte(length(Filter(function(.x) !is.null(.x), all_history$files)), 1)
-      expect_equal(min(all_history$ts), post1$ts)
-      expect_equal(max(all_history$ts), post4$ts)
-
-      all_history <- slackr_history(
-        message_count = 1000,
-        posted_from_time = post1$ts,
-        posted_to_time = post2$ts,
-        paginate = paginate
-      )
-
-      expect_gte(nrow(all_history), 2)
-      expect_lte(min(as.numeric(all_history$ts)), as.numeric(post1$ts))
-      expect_gte(max(as.numeric(all_history$ts)), as.numeric(post2$ts))
-    }
-  )
-})
-
-test_that("Specifying post times in slackr_history correctly limits time window", {
-  skip_on_cran()
-
-  lapply(
-    c(TRUE, FALSE),
-    function(paginate) {
-      post1 <- slackr_msg("History test post 1.")
-
-      Sys.sleep(1)
-
-      post2 <- slackr_msg("History test post 2.")
-
-      Sys.sleep(1)
-      post3 <- slackr_msg("History test post 4.")
-
-      all_history <- slackr_history(
-        message_count = 1000,
-        posted_from_time = post1$ts,
-        posted_to_time = post2$ts,
-        paginate = paginate
-      )
-
-      expect_lte(min(as.numeric(all_history$ts)), as.numeric(post1$ts))
-      expect_gte(max(as.numeric(all_history$ts)), as.numeric(post2$ts))
-      expect_lt(as.numeric(max(all_history$ts)), as.numeric(post3$ts))
-    }
-  )
-})
-
-test_that("Expect warning for too many params", {
-  skip_on_cran()
-
-  from_time <- slackr_msg("History warning test start")$ts
-  Sys.sleep(1)
-  slackr_msg("History warning test")
-  Sys.sleep(1)
-  to_time <- slackr_msg("History warning test end")$ts
-
-  expect_silent(
-    slackr_history(
-      posted_to_time = to_time,
-      duration = 2 * (as.numeric(to_time) - as.numeric(from_time)) / (60 * 60)
-    )
-  )
-
-  expect_warning(
-    slackr_history(
-      posted_from_time = from_time,
-      posted_to_time = to_time,
-      duration = 2 * (as.numeric(to_time) - as.numeric(from_time)) / (60 * 60)
-    ),
-    "You specified all three of"
-  )
-})
-
-test_that("Error if trying to paginate with no start time", {
-  skip_on_cran()
-
-  expect_error(
-    slackr_history(
-      paginate = TRUE
-    ),
-    "To use pagination with `slackr_history`, you must specify a value for `posted_from_time`"
-  )
-})
diff --git a/tests/testthat/test-internals.R b/tests/testthat/test-internals.R
index c145353..4d9b755 100644
--- a/tests/testthat/test-internals.R
+++ b/tests/testthat/test-internals.R
@@ -52,7 +52,7 @@ test_that("Channels works", {
 
   expect_equal(
     ncol(channels),
-    28
+    29
   )
 
   expect_gte(