diff --git a/mix.exs b/mix.exs
index 0508a43..3e3466f 100644
--- a/mix.exs
+++ b/mix.exs
@@ -71,7 +71,6 @@ defmodule Cldr.Calendar.MixProject do
       {:ex_doc, "~> 0.21", optional: true, runtime: false},
       {:benchee, "~> 1.0", optional: true, only: [:dev, :test]},
       {:dialyxir, "~> 1.0", optional: true, only: [:dev, :test], runtime: false},
-      {:nimble_strftime, "~> 0.1", only: :test},
       {:stream_data, "~> 1.0", only: :test}
     ]
   end
diff --git a/test/strftime_options_test.exs b/test/strftime_options_test.exs
index 3c1cf3c..67e2375 100644
--- a/test/strftime_options_test.exs
+++ b/test/strftime_options_test.exs
@@ -50,28 +50,28 @@ defmodule Cldr.Calendar.StrftimeOptions.Test do
   end
 
   test "strftime with options" do
-    assert NimbleStrftime.format(
+    assert Calendar.strftime(
              ~D[2019-11-03],
              "%a, %B %d %Y",
              MyApp.Cldr.Calendar.strftime_options!()
            ) ==
              "Sun, November 03 2019"
 
-    assert NimbleStrftime.format(
+    assert Calendar.strftime(
              ~D[2019-11-03],
              "%A, %b %d %Y",
              MyApp.Cldr.Calendar.strftime_options!()
            ) ==
              "Sunday, Nov 03 2019"
 
-    assert NimbleStrftime.format(
+    assert Calendar.strftime(
              ~D[2019-11-03],
              "%A, %b %d %Y",
              MyApp.Cldr.Calendar.strftime_options!("fr")
            ) ==
              "dimanche, nov. 03 2019"
 
-    assert NimbleStrftime.format(
+    assert Calendar.strftime(
              ~D[2019-11-03],
              "%A, %B %d %Y",
              MyApp.Cldr.Calendar.strftime_options!("he")
@@ -80,14 +80,14 @@ defmodule Cldr.Calendar.StrftimeOptions.Test do
 
     {:ok, dt} = NaiveDateTime.new(2019, 8, 26, 13, 52, 06, 0)
 
-    assert NimbleStrftime.format(
+    assert Calendar.strftime(
              dt,
              "%y-%m-%d %I:%M:%S %p",
              MyApp.Cldr.Calendar.strftime_options!("fr")
            ) ==
              "19-08-26 01:52:06 PM"
 
-    assert NimbleStrftime.format(
+    assert Calendar.strftime(
              dt,
              "%y-%m-%d %I:%M:%S %p",
              MyApp.Cldr.Calendar.strftime_options!("he")
@@ -95,7 +95,7 @@ defmodule Cldr.Calendar.StrftimeOptions.Test do
              "19-08-26 01:52:06 אחה״צ"
 
     assert_raise Cldr.InvalidLanguageError, fn ->
-      NimbleStrftime.format(
+      Calendar.strftime(
         dt,
         "%y-%m-%d %I:%M:%S %p",
         MyApp.Cldr.Calendar.strftime_options!("zz")