diff --git a/lib/pleroma/http/request_builder.ex b/lib/pleroma/http/request_builder.ex
index e23457999..4e77870bd 100644
--- a/lib/pleroma/http/request_builder.ex
+++ b/lib/pleroma/http/request_builder.ex
@@ -48,7 +48,7 @@ defmodule Pleroma.HTTP.RequestBuilder do
   def headers(request, header_list) do
     header_list =
       if Pleroma.Config.get([:http, :send_user_agent]) do
-        header_list ++ [{"User-Agent", Pleroma.Application.user_agent()}]
+        header_list ++ [{"user-agent", Pleroma.Application.user_agent()}]
       else
         header_list
       end
diff --git a/lib/pleroma/object/fetcher.ex b/lib/pleroma/object/fetcher.ex
index 8d79ddb1f..46531a13a 100644
--- a/lib/pleroma/object/fetcher.ex
+++ b/lib/pleroma/object/fetcher.ex
@@ -95,7 +95,7 @@ defmodule Pleroma.Object.Fetcher do
         date: date
       })
 
-    [{:Signature, signature}]
+    [{"signature", signature}]
   end
 
   defp sign_fetch(headers, id, date) do
@@ -108,7 +108,7 @@ defmodule Pleroma.Object.Fetcher do
 
   defp maybe_date_fetch(headers, date) do
     if Pleroma.Config.get([:activitypub, :sign_object_fetches]) do
-      headers ++ [{:Date, date}]
+      headers ++ [{"date", date}]
     else
       headers
     end
@@ -122,7 +122,7 @@ defmodule Pleroma.Object.Fetcher do
       |> Timex.format!("{WDshort}, {0D} {Mshort} {YYYY} {h24}:{m}:{s} GMT")
 
     headers =
-      [{:Accept, "application/activity+json"}]
+      [{"accept", "application/activity+json"}]
       |> maybe_date_fetch(date)
       |> sign_fetch(id, date)
 
diff --git a/lib/pleroma/web/ostatus/ostatus.ex b/lib/pleroma/web/ostatus/ostatus.ex
index 331cbc0b7..1c400d9e4 100644
--- a/lib/pleroma/web/ostatus/ostatus.ex
+++ b/lib/pleroma/web/ostatus/ostatus.ex
@@ -373,7 +373,7 @@ defmodule Pleroma.Web.OStatus do
          {:ok, %{body: body, status: code}} when code in 200..299 <-
            HTTP.get(
              url,
-             [{:Accept, "application/atom+xml"}]
+             [{"accept", "application/atom+xml"}]
            ) do
       Logger.debug("Got document from #{url}, handling...")
       handle_incoming(body, options)
diff --git a/lib/pleroma/web/web_finger/web_finger.ex b/lib/pleroma/web/web_finger/web_finger.ex
index ecb39ee50..624ee5ef7 100644
--- a/lib/pleroma/web/web_finger/web_finger.ex
+++ b/lib/pleroma/web/web_finger/web_finger.ex
@@ -217,7 +217,7 @@ defmodule Pleroma.Web.WebFinger do
     with response <-
            HTTP.get(
              address,
-             Accept: "application/xrd+xml,application/jrd+json"
+             [{"accept", "application/xrd+xml,application/jrd+json"}]
            ),
          {:ok, %{status: status, body: body}} when status in 200..299 <- response do
       doc = XML.parse_document(body)
diff --git a/test/http/request_builder_test.exs b/test/http/request_builder_test.exs
index 7febe84c5..5a645d4f3 100644
--- a/test/http/request_builder_test.exs
+++ b/test/http/request_builder_test.exs
@@ -20,7 +20,7 @@ defmodule Pleroma.HTTP.RequestBuilderTest do
       end)
 
       assert RequestBuilder.headers(%{}, []) == %{
-               headers: [{"User-Agent", Pleroma.Application.user_agent()}]
+               headers: [{"user-agent", Pleroma.Application.user_agent()}]
              }
     end
   end
diff --git a/test/support/http_request_mock.ex b/test/support/http_request_mock.ex
index 3adb5ba3b..c4862eb1c 100644
--- a/test/support/http_request_mock.ex
+++ b/test/support/http_request_mock.ex
@@ -88,7 +88,7 @@ defmodule HttpRequestMock do
         "https://osada.macgirvin.com/.well-known/webfinger?resource=acct:mike@osada.macgirvin.com",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -101,7 +101,7 @@ defmodule HttpRequestMock do
         "https://social.heldscal.la/.well-known/webfinger?resource=https://social.heldscal.la/user/29191",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -122,7 +122,7 @@ defmodule HttpRequestMock do
         "https://pawoo.net/.well-known/webfinger?resource=acct:https://pawoo.net/users/pekorino",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -148,7 +148,7 @@ defmodule HttpRequestMock do
         "https://social.stopwatchingus-heidelberg.de/.well-known/webfinger?resource=acct:https://social.stopwatchingus-heidelberg.de/user/18330",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -169,7 +169,7 @@ defmodule HttpRequestMock do
         "https://mamot.fr/.well-known/webfinger?resource=acct:https://mamot.fr/users/Skruyb",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -182,7 +182,7 @@ defmodule HttpRequestMock do
         "https://social.heldscal.la/.well-known/webfinger?resource=nonexistant@social.heldscal.la",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -195,7 +195,7 @@ defmodule HttpRequestMock do
         "https://squeet.me/xrd/?uri=lain@squeet.me",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -208,7 +208,7 @@ defmodule HttpRequestMock do
         "https://mst3k.interlinked.me/users/luciferMysticus",
         _,
         _,
-        Accept: "application/activity+json"
+        [{"accept", "application/activity+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -229,7 +229,7 @@ defmodule HttpRequestMock do
         "https://hubzilla.example.org/channel/kaniini",
         _,
         _,
-        Accept: "application/activity+json"
+        [{"accept", "application/activity+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -238,7 +238,7 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("https://niu.moe/users/rye", _, _, Accept: "application/activity+json") do
+  def get("https://niu.moe/users/rye", _, _, [{"accept", "application/activity+json"}]) do
     {:ok,
      %Tesla.Env{
        status: 200,
@@ -246,7 +246,7 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("https://n1u.moe/users/rye", _, _, Accept: "application/activity+json") do
+  def get("https://n1u.moe/users/rye", _, _, [{"accept", "application/activity+json"}]) do
     {:ok,
      %Tesla.Env{
        status: 200,
@@ -265,7 +265,7 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("https://puckipedia.com/", _, _, Accept: "application/activity+json") do
+  def get("https://puckipedia.com/", _, _, [{"accept", "application/activity+json"}]) do
     {:ok,
      %Tesla.Env{
        status: 200,
@@ -321,7 +321,9 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("http://mastodon.example.org/users/admin", _, _, Accept: "application/activity+json") do
+  def get("http://mastodon.example.org/users/admin", _, _, [
+        {"accept", "application/activity+json"}
+      ]) do
     {:ok,
      %Tesla.Env{
        status: 200,
@@ -329,7 +331,9 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("http://mastodon.example.org/users/gargron", _, _, Accept: "application/activity+json") do
+  def get("http://mastodon.example.org/users/gargron", _, _, [
+        {"accept", "application/activity+json"}
+      ]) do
     {:error, :nxdomain}
   end
 
@@ -337,7 +341,7 @@ defmodule HttpRequestMock do
         "http://mastodon.example.org/@admin/99541947525187367",
         _,
         _,
-        Accept: "application/activity+json"
+        [{"accept", "application/activity+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -354,7 +358,7 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("https://mstdn.io/users/mayuutann", _, _, Accept: "application/activity+json") do
+  def get("https://mstdn.io/users/mayuutann", _, _, [{"accept", "application/activity+json"}]) do
     {:ok,
      %Tesla.Env{
        status: 200,
@@ -366,7 +370,7 @@ defmodule HttpRequestMock do
         "https://mstdn.io/users/mayuutann/statuses/99568293732299394",
         _,
         _,
-        Accept: "application/activity+json"
+        [{"accept", "application/activity+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -386,7 +390,7 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get(url, _, _, Accept: "application/xrd+xml,application/jrd+json")
+  def get(url, _, _, [{"accept", "application/xrd+xml,application/jrd+json"}])
       when url in [
              "https://pleroma.soykaf.com/.well-known/webfinger?resource=acct:https://pleroma.soykaf.com/users/lain",
              "https://pleroma.soykaf.com/.well-known/webfinger?resource=https://pleroma.soykaf.com/users/lain"
@@ -413,7 +417,7 @@ defmodule HttpRequestMock do
         "https://shitposter.club/.well-known/webfinger?resource=https://shitposter.club/user/1",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -457,7 +461,7 @@ defmodule HttpRequestMock do
         "https://shitposter.club/.well-known/webfinger?resource=https://shitposter.club/user/5381",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -510,7 +514,7 @@ defmodule HttpRequestMock do
         "https://social.sakamoto.gq/.well-known/webfinger?resource=https://social.sakamoto.gq/users/eal",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -523,7 +527,7 @@ defmodule HttpRequestMock do
         "https://social.sakamoto.gq/objects/0ccc1a2c-66b0-4305-b23a-7f7f2b040056",
         _,
         _,
-        Accept: "application/atom+xml"
+        [{"accept", "application/atom+xml"}]
       ) do
     {:ok, %Tesla.Env{status: 200, body: File.read!("test/fixtures/tesla_mock/sakamoto.atom")}}
   end
@@ -540,7 +544,7 @@ defmodule HttpRequestMock do
         "https://mastodon.social/.well-known/webfinger?resource=https://mastodon.social/users/lambadalambda",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -562,7 +566,7 @@ defmodule HttpRequestMock do
         "http://gs.example.org/.well-known/webfinger?resource=http://gs.example.org:4040/index.php/user/1",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -576,7 +580,7 @@ defmodule HttpRequestMock do
         "http://gs.example.org:4040/index.php/user/1",
         _,
         _,
-        Accept: "application/activity+json"
+        [{"accept", "application/activity+json"}]
       ) do
     {:ok, %Tesla.Env{status: 406, body: ""}}
   end
@@ -612,7 +616,7 @@ defmodule HttpRequestMock do
         "https://squeet.me/xrd?uri=lain@squeet.me",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -625,7 +629,7 @@ defmodule HttpRequestMock do
         "https://social.heldscal.la/.well-known/webfinger?resource=shp@social.heldscal.la",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -638,7 +642,7 @@ defmodule HttpRequestMock do
         "https://social.heldscal.la/.well-known/webfinger?resource=invalid_content@social.heldscal.la",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok, %Tesla.Env{status: 200, body: ""}}
   end
@@ -655,7 +659,7 @@ defmodule HttpRequestMock do
         "http://framatube.org/main/xrd?uri=framasoft@framatube.org",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -677,7 +681,7 @@ defmodule HttpRequestMock do
         "http://gnusocial.de/main/xrd?uri=winterdienst@gnusocial.de",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -714,7 +718,7 @@ defmodule HttpRequestMock do
         "https://gerzilla.de/xrd/?uri=kaniini@gerzilla.de",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -772,7 +776,7 @@ defmodule HttpRequestMock do
     {:ok, %Tesla.Env{status: 200, body: File.read!("test/fixtures/lambadalambda.json")}}
   end
 
-  def get("https://social.heldscal.la/user/23211", _, _, Accept: "application/activity+json") do
+  def get("https://social.heldscal.la/user/23211", _, _, [{"accept", "application/activity+json"}]) do
     {:ok, Tesla.Mock.json(%{"id" => "https://social.heldscal.la/user/23211"}, status: 200)}
   end
 
@@ -889,7 +893,7 @@ defmodule HttpRequestMock do
         "https://zetsubou.xn--q9jyb4c/.well-known/webfinger?resource=lain@zetsubou.xn--q9jyb4c",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -902,7 +906,7 @@ defmodule HttpRequestMock do
         "https://zetsubou.xn--q9jyb4c/.well-known/webfinger?resource=https://zetsubou.xn--q9jyb4c/users/lain",
         _,
         _,
-        Accept: "application/xrd+xml,application/jrd+json"
+        [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
     {:ok,
      %Tesla.Env{
@@ -924,7 +928,9 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("https://info.pleroma.site/activity.json", _, _, Accept: "application/activity+json") do
+  def get("https://info.pleroma.site/activity.json", _, _, [
+        {"accept", "application/activity+json"}
+      ]) do
     {:ok,
      %Tesla.Env{
        status: 200,
@@ -936,7 +942,9 @@ defmodule HttpRequestMock do
     {:ok, %Tesla.Env{status: 404, body: ""}}
   end
 
-  def get("https://info.pleroma.site/activity2.json", _, _, Accept: "application/activity+json") do
+  def get("https://info.pleroma.site/activity2.json", _, _, [
+        {"accept", "application/activity+json"}
+      ]) do
     {:ok,
      %Tesla.Env{
        status: 200,
@@ -948,7 +956,9 @@ defmodule HttpRequestMock do
     {:ok, %Tesla.Env{status: 404, body: ""}}
   end
 
-  def get("https://info.pleroma.site/activity3.json", _, _, Accept: "application/activity+json") do
+  def get("https://info.pleroma.site/activity3.json", _, _, [
+        {"accept", "application/activity+json"}
+      ]) do
     {:ok,
      %Tesla.Env{
        status: 200,
diff --git a/test/web/twitter_api/util_controller_test.exs b/test/web/twitter_api/util_controller_test.exs
index 640579c09..b55656ae9 100644
--- a/test/web/twitter_api/util_controller_test.exs
+++ b/test/web/twitter_api/util_controller_test.exs
@@ -11,6 +11,7 @@ defmodule Pleroma.Web.TwitterAPI.UtilControllerTest do
   alias Pleroma.Web.CommonAPI
   import Pleroma.Factory
   import Mock
+  import ExUnit.CaptureLog
 
   setup do
     Tesla.Mock.mock(fn env -> apply(HttpRequestMock, :request, [env]) end)
@@ -377,15 +378,18 @@ defmodule Pleroma.Web.TwitterAPI.UtilControllerTest do
       assert html_response(response, 200) =~ "Remote follow"
     end
 
-    test "show follow page with error when user cannot fecth by `acct` link", %{conn: conn} do
+    test "show follow page with error when user cannot fetch by `acct` link", %{conn: conn} do
       user = insert(:user)
 
-      response =
-        conn
-        |> assign(:user, user)
-        |> get("/ostatus_subscribe?acct=https://mastodon.social/users/not_found")
+      assert capture_log(fn ->
+               response =
+                 conn
+                 |> assign(:user, user)
+                 |> get("/ostatus_subscribe?acct=https://mastodon.social/users/not_found")
 
-      assert html_response(response, 200) =~ "Error fetching user"
+               assert html_response(response, 200) =~ "Error fetching user"
+             end) =~
+               "Could not decode user at fetch https://mastodon.social/users/not_found, {:error, \"Object has been deleted\"}"
     end
   end
 
diff --git a/test/web/web_finger/web_finger_controller_test.exs b/test/web/web_finger/web_finger_controller_test.exs
index 7d861cbf5..d9c24b8d5 100644
--- a/test/web/web_finger/web_finger_controller_test.exs
+++ b/test/web/web_finger/web_finger_controller_test.exs
@@ -7,6 +7,7 @@ defmodule Pleroma.Web.WebFinger.WebFingerControllerTest do
 
   import Pleroma.Factory
   import Tesla.Mock
+  import ExUnit.CaptureLog
 
   setup do
     mock(fn env -> apply(HttpRequestMock, :request, [env]) end)
@@ -77,11 +78,13 @@ defmodule Pleroma.Web.WebFinger.WebFingerControllerTest do
   test "Sends a 404 when invalid format" do
     user = insert(:user)
 
-    assert_raise Phoenix.NotAcceptableError, fn ->
-      build_conn()
-      |> put_req_header("accept", "text/html")
-      |> get("/.well-known/webfinger?resource=acct:#{user.nickname}@localhost")
-    end
+    assert capture_log(fn ->
+             assert_raise Phoenix.NotAcceptableError, fn ->
+               build_conn()
+               |> put_req_header("accept", "text/html")
+               |> get("/.well-known/webfinger?resource=acct:#{user.nickname}@localhost")
+             end
+           end) =~ "Internal server error:"
   end
 
   test "Sends a 400 when resource param is missing" do