diff --git a/lib/x509/test/crl_server.ex b/lib/x509/test/crl_server.ex
index 74ea3e9..4522af7 100644
--- a/lib/x509/test/crl_server.ex
+++ b/lib/x509/test/crl_server.ex
@@ -3,7 +3,6 @@ defmodule X509.Test.CRLServer do
   Simple CRL responder for use in test suites.
   """
   use GenServer
-  require Logger
 
   @doc """
   Starts a CRL responder.
@@ -107,7 +106,7 @@ defmodule X509.Test.CRLServer do
       {:ok, :http_eoh} ->
         case Map.get(crl_map, path) do
           nil ->
-            Logger.warn("No CRL defined for #{path}")
+            X509.Util.warn("No CRL defined for #{path}")
             respond(socket, 404)
             :gen_tcp.close(socket)
 
diff --git a/lib/x509/test/suite.ex b/lib/x509/test/suite.ex
index 35c6bf3..6c24060 100644
--- a/lib/x509/test/suite.ex
+++ b/lib/x509/test/suite.ex
@@ -63,8 +63,6 @@ defmodule X509.Test.Suite do
   * `client-cert` - requires that the client present a valid certificate
   """
 
-  require Logger
-
   defstruct [
     :domain,
     :key_type,
@@ -582,7 +580,7 @@ defmodule X509.Test.Suite do
         %__MODULE__{valid: valid, chain: chain, server_key: server_key},
         scenario
       ) do
-    Logger.warn("Unknown scenario: #{scenario}")
+    X509.Util.warn("Unknown scenario: #{scenario}")
 
     [
       cert: X509.Certificate.to_der(valid),
diff --git a/lib/x509/util.ex b/lib/x509/util.ex
index 7497df2..5d218e3 100644
--- a/lib/x509/util.ex
+++ b/lib/x509/util.ex
@@ -1,6 +1,8 @@
 defmodule X509.Util do
   @moduledoc false
 
+  require Logger
+
   def app_version(application) do
     application
     |> Application.spec()
@@ -9,4 +11,16 @@ defmodule X509.Util do
     |> String.split(".")
     |> Enum.map(&String.to_integer/1)
   end
+
+  # Create a utility function that handles checking for the 
+  # existence of Logger.warning/2 if not fallback to Logger.warn/2
+  if macro_exported?(Logger, :warning, 2) do
+    def warn(message, metadata \\ []) do
+      Logger.warning(message, metadata)
+    end
+  else
+    def warn(message, metadata \\ []) do
+      Logger.warn(message, metadata)
+    end
+  end
 end
diff --git a/test/x509/test/server_test.exs b/test/x509/test/server_test.exs
index 2433a08..394887b 100644
--- a/test/x509/test/server_test.exs
+++ b/test/x509/test/server_test.exs
@@ -25,7 +25,6 @@ defmodule X509.Test.ServerTest do
 
   use ExUnit.Case
   import X509.TestHelper
-  require Logger
 
   #
   # Client under test
@@ -839,7 +838,7 @@ defmodule X509.Test.ServerTest do
       end
     end
   else
-    Logger.warn("ECDSA certificates can't be tested on the current OTP version")
+    X509.Util.warn("ECDSA certificates can't be tested on the current OTP version")
   end
 
   #