diff --git a/config/config.exs b/config/config.exs
index d6f4dd5..de0f2cb 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -1,30 +1,3 @@
-# This file is responsible for configuring your application
-# and its dependencies with the aid of the Mix.Config module.
-use Mix.Config
+import Config
 
-# This configuration is loaded before any dependency and is restricted
-# to this project. If another project depends on this project, this
-# file won't be loaded nor affect the parent project. For this reason,
-# if you want to provide default values for your application for
-# 3rd-party users, it should be done in your "mix.exs" file.
-
-# You can configure for your application as:
-#
-#     config :shopify, key: :value
-#
-# And access this configuration in your application as:
-#
-#     Application.get_env(:shopify, :key)
-#
-# Or configure a 3rd-party app:
-#
-#     config :logger, level: :info
-#
-
-# It is also possible to import configuration files, relative to this
-# directory. For example, you can emulate configuration per environment
-# by uncommenting the line below and defining dev.exs, test.exs and such.
-# Configuration from the imported file will override the ones defined
-# here (which is why it is important to import them last).
-#
-import_config "#{Mix.env()}.exs"
+import_config("#{config_env()}.exs")
diff --git a/config/dev.exs b/config/dev.exs
index 368a76a..a3f14d3 100644
--- a/config/dev.exs
+++ b/config/dev.exs
@@ -1,3 +1,3 @@
-use Mix.Config
+import Config
 
 config :shopify, client_adapter: Shopify.Adapters.HTTP
diff --git a/config/prod.ex b/config/prod.ex
index 368a76a..a3f14d3 100644
--- a/config/prod.ex
+++ b/config/prod.ex
@@ -1,3 +1,3 @@
-use Mix.Config
+import Config
 
 config :shopify, client_adapter: Shopify.Adapters.HTTP
diff --git a/config/test.exs b/config/test.exs
index d7ddcd2..77b0017 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -1,4 +1,4 @@
-use Mix.Config
+import Config
 
 config :shopify,
   client_adapter: Shopify.Adapters.Mock,
diff --git a/lib/shopify/multipass.ex b/lib/shopify/multipass.ex
index 96fc735..2415874 100644
--- a/lib/shopify/multipass.ex
+++ b/lib/shopify/multipass.ex
@@ -5,8 +5,7 @@ defmodule Shopify.Multipass do
   [https://help.shopify.com/en/api/reference/plus/multipass](https://help.shopify.com/en/api/reference/plus/multipass)
   """
 
-  # The size of the crypto used by http://erlang.org/doc/man/crypto.html#block_encrypt-4
-  # Refer to the erlang docs as to which block sizes are allowed
+  # The size of the crypto used
   @block_size 16
 
   @doc ~S"""
@@ -64,7 +63,6 @@ defmodule Shopify.Multipass do
   @doc ~S"""
   Pads the message string with extra bytes to ensure it is evenly divisible by
   the block size.
-  See [http://erlang.org/doc/man/crypto.html#block_encrypt-4](http://erlang.org/doc/man/crypto.html#block_encrypt-4)
   """
   @spec pad(binary, integer) :: binary
   def pad(string, block_size \\ @block_size) do
@@ -81,11 +79,12 @@ defmodule Shopify.Multipass do
     initialization_vector = :crypto.strong_rand_bytes(block_size)
 
     initialization_vector <>
-      :crypto.block_encrypt(
-        :aes_cbc128,
+      :crypto.crypto_one_time(
+        :aes_128_cbc,
         encryption_key,
         initialization_vector,
-        pad(message, block_size)
+        pad(message, block_size),
+        true
       )
   end
 
@@ -94,7 +93,7 @@ defmodule Shopify.Multipass do
   """
   @spec sign(binary, binary) :: binary
   def sign(cipher_text, signature_key) do
-    signature = :crypto.hmac(:sha256, signature_key, cipher_text)
+    signature = :crypto.mac(:hmac, :sha256, signature_key, cipher_text)
     cipher_text <> signature
   end
 
diff --git a/lib/shopify/resources/webhook.ex b/lib/shopify/resources/webhook.ex
index 67587fb..4be8348 100644
--- a/lib/shopify/resources/webhook.ex
+++ b/lib/shopify/resources/webhook.ex
@@ -44,7 +44,7 @@ defmodule Shopify.Webhook do
       
   """
   def authenticate(hmac, body) when is_binary(hmac) and is_binary(body) do
-    :crypto.hmac(:sha256, Config.get(:client_secret), body)
+    :crypto.mac(:hmac, :sha256, Config.get(:client_secret), body)
     |> Base.encode64()
     |> String.equivalent?(hmac)
   end
diff --git a/mix.exs b/mix.exs
index 03f721c..43ce6d0 100644
--- a/mix.exs
+++ b/mix.exs
@@ -56,7 +56,7 @@ defmodule Shopify.Mixfile do
   defp deps do
     [
       {:httpoison, "~> 1.0"},
-      {:poison, "~> 3.0"},
+      {:poison, "~> 5.0"},
       {:ex_doc, "~> 0.19", only: :dev, runtime: false}
     ]
   end
diff --git a/mix.lock b/mix.lock
index ca37ea9..6d89e2e 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,17 +1,19 @@
 %{
-  "certifi": {:hex, :certifi, "2.4.2", "75424ff0f3baaccfd34b1214184b6ef616d89e420b258bb0a5ea7d7bc628f7f0", [:rebar3], [{:parse_trans, "~>3.3", [hex: :parse_trans, repo: "hexpm", optional: false]}], "hexpm"},
-  "earmark": {:hex, :earmark, "1.3.0", "17f0c38eaafb4800f746b457313af4b2442a8c2405b49c645768680f900be603", [:mix], [], "hexpm"},
-  "ex_doc": {:hex, :ex_doc, "0.19.1", "519bb9c19526ca51d326c060cb1778d4a9056b190086a8c6c115828eaccea6cf", [:mix], [{:earmark, "~> 1.1", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.7", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm"},
-  "hackney": {:hex, :hackney, "1.15.0", "287a5d2304d516f63e56c469511c42b016423bcb167e61b611f6bad47e3ca60e", [:rebar3], [{:certifi, "2.4.2", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "6.0.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.4", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm"},
-  "httpoison": {:hex, :httpoison, "1.5.0", "71ae9f304bdf7f00e9cd1823f275c955bdfc68282bc5eb5c85c3a9ade865d68e", [:mix], [{:hackney, "~> 1.8", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm"},
-  "idna": {:hex, :idna, "6.0.0", "689c46cbcdf3524c44d5f3dde8001f364cd7608a99556d8fbd8239a5798d4c10", [:rebar3], [{:unicode_util_compat, "0.4.1", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm"},
-  "makeup": {:hex, :makeup, "0.5.5", "9e08dfc45280c5684d771ad58159f718a7b5788596099bdfb0284597d368a882", [:mix], [{:nimble_parsec, "~> 0.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.10.0", "0f09c2ddf352887a956d84f8f7e702111122ca32fbbc84c2f0569b8b65cbf7fa", [:mix], [{:makeup, "~> 0.5.5", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm"},
-  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm"},
-  "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], [], "hexpm"},
-  "nimble_parsec": {:hex, :nimble_parsec, "0.4.0", "ee261bb53214943679422be70f1658fff573c5d0b0a1ecd0f18738944f818efe", [:mix], [], "hexpm"},
-  "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm"},
-  "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [:mix], [], "hexpm"},
-  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.4", "f0eafff810d2041e93f915ef59899c923f4568f4585904d010387ed74988e77b", [:make, :mix, :rebar3], [], "hexpm"},
-  "unicode_util_compat": {:hex, :unicode_util_compat, "0.4.1", "d869e4c68901dd9531385bb0c8c40444ebf624e60b6962d95952775cac5e90cd", [:rebar3], [], "hexpm"},
+  "certifi": {:hex, :certifi, "2.9.0", "6f2a475689dd47f19fb74334859d460a2dc4e3252a3324bd2111b8f0429e7e21", [:rebar3], [], "hexpm", "266da46bdb06d6c6d35fde799bcb28d36d985d424ad7c08b5bb48f5b5cdd4641"},
+  "earmark": {:hex, :earmark, "1.3.0", "17f0c38eaafb4800f746b457313af4b2442a8c2405b49c645768680f900be603", [:mix], [], "hexpm", "f8b8820099caf0d5e72ae6482d2b0da96f213cbbe2b5b2191a37966e119eaa27"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.29", "149d50dcb3a93d9f3d6f3ecf18c918fb5a2d3c001b5d3305c926cddfbd33355b", [:mix], [], "hexpm", "4902af1b3eb139016aed210888748db8070b8125c2342ce3dcae4f38dcc63503"},
+  "ex_doc": {:hex, :ex_doc, "0.29.1", "b1c652fa5f92ee9cf15c75271168027f92039b3877094290a75abcaac82a9f77", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "b7745fa6374a36daf484e2a2012274950e084815b936b1319aeebcf7809574f6"},
+  "hackney": {:hex, :hackney, "1.18.1", "f48bf88f521f2a229fc7bae88cf4f85adc9cd9bcf23b5dc8eb6a1788c662c4f6", [:rebar3], [{:certifi, "~> 2.9.0", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~> 6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~> 1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~> 1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~> 1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~> 0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "a4ecdaff44297e9b5894ae499e9a070ea1888c84afdd1fd9b7b2bc384950128e"},
+  "httpoison": {:hex, :httpoison, "1.8.2", "9eb9c63ae289296a544842ef816a85d881d4a31f518a0fec089aaa744beae290", [:mix], [{:hackney, "~> 1.17", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm", "2bb350d26972e30c96e2ca74a1aaf8293d61d0742ff17f01e0279fef11599921"},
+  "idna": {:hex, :idna, "6.1.1", "8a63070e9f7d0c62eb9d9fcb360a7de382448200fbbd1b106cc96d3d8099df8d", [:rebar3], [{:unicode_util_compat, "~> 0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "92376eb7894412ed19ac475e4a86f7b413c1b9fbb5bd16dccd57934157944cea"},
+  "makeup": {:hex, :makeup, "1.1.0", "6b67c8bc2882a6b6a445859952a602afc1a41c2e08379ca057c0f525366fc3ca", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "0a45ed501f4a8897f580eabf99a2e5234ea3e75a4373c8a52824f6e873be57a6"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.16.0", "f8c570a0d33f8039513fbccaf7108c5d750f47d8defd44088371191b76492b0b", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "28b2cbdc13960a46ae9a8858c4bebdec3c9a6d7b4b9e7f4ed1502f8159f338e7"},
+  "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
+  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm", "69b09adddc4f74a40716ae54d140f93beb0fb8978d8636eaded0c31b6f099f16"},
+  "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.2.3", "244836e6e3f1200c7f30cb56733fd808744eca61fd182f731eac4af635cc6d0b", [:mix], [], "hexpm", "c8d789e39b9131acf7b99291e93dae60ab48ef14a7ee9d58c6964f59efb570b0"},
+  "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
+  "poison": {:hex, :poison, "5.0.0", "d2b54589ab4157bbb82ec2050757779bfed724463a544b6e20d79855a9e43b24", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "11dc6117c501b80c62a7594f941d043982a1bd05a1184280c0d9166eb4d8d3fc"},
+  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
+  "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
 }
diff --git a/test/webhook_test.exs b/test/webhook_test.exs
index 97608f6..268f4cb 100644
--- a/test/webhook_test.exs
+++ b/test/webhook_test.exs
@@ -64,13 +64,19 @@ defmodule Shopify.WebhookTest do
 
   test "authorized webhooks will return true" do
     body = ~s({"foo": "bar"})
-    hmac = :crypto.hmac(:sha256, Shopify.Config.get(:client_secret), body) |> Base.encode64()
+
+    hmac =
+      :crypto.mac(:hmac, :sha256, Shopify.Config.get(:client_secret), body) |> Base.encode64()
+
     assert Webhook.authenticate(hmac, body)
   end
 
   test "unauthorized webhooks will return false" do
     body = ~s({"foo": "bar"})
-    hmac = :crypto.hmac(:sha256, Shopify.Config.get(:client_secret), body) |> Base.encode64()
+
+    hmac =
+      :crypto.mac(:hmac, :sha256, Shopify.Config.get(:client_secret), body) |> Base.encode64()
+
     refute Webhook.authenticate(hmac, ~s({"foo": "baz"}))
   end
 end