diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 747a83e8d..47c51469e 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -758,13 +758,26 @@ defmodule Pleroma.User do
       valid? =
         Config.get([User, :email_blacklist])
         |> Enum.all?(fn blacklisted_domain ->
-          !String.ends_with?(email, ["@" <> blacklisted_domain, "." <> blacklisted_domain])
+          blacklisted_domain_downcase = String.downcase(blacklisted_domain)
+
+          !String.ends_with?(String.downcase(email), [
+            "@" <> blacklisted_domain_downcase,
+            "." <> blacklisted_domain_downcase
+          ])
         end)
 
       if valid?, do: [], else: [email: "Invalid email"]
     end)
     |> unique_constraint(:nickname)
-    |> validate_exclusion(:nickname, Config.get([User, :restricted_nicknames]))
+    |> validate_change(:nickname, fn :nickname, nickname ->
+      valid? =
+        Config.get([User, :restricted_nicknames])
+        |> Enum.all?(fn restricted_nickname ->
+          String.downcase(nickname) != String.downcase(restricted_nickname)
+        end)
+
+      if valid?, do: [], else: [nickname: "Invalid nickname"]
+    end)
     |> validate_format(:nickname, local_nickname_regex())
     |> validate_length(:bio, max: bio_limit)
     |> validate_length(:name, min: 1, max: name_limit)
diff --git a/test/pleroma/user_test.exs b/test/pleroma/user_test.exs
index 884b846ae..5b513f01b 100644
--- a/test/pleroma/user_test.exs
+++ b/test/pleroma/user_test.exs
@@ -618,6 +618,7 @@ defmodule Pleroma.UserTest do
     end
 
     test "it restricts certain nicknames" do
+      clear_config([User, :restricted_nicknames], ["about"])
       [restricted_name | _] = Pleroma.Config.get([User, :restricted_nicknames])
 
       assert is_bitstring(restricted_name)
@@ -631,6 +632,23 @@ defmodule Pleroma.UserTest do
       refute changeset.valid?
     end
 
+    test "it is case-insensitive when restricting nicknames" do
+      clear_config([User, :restricted_nicknames], ["about"])
+      [restricted_name | _] = Pleroma.Config.get([User, :restricted_nicknames])
+
+      assert is_bitstring(restricted_name)
+
+      restricted_upcase_name = String.upcase(restricted_name)
+
+      params =
+        @full_user_data
+        |> Map.put(:nickname, restricted_upcase_name)
+
+      changeset = User.register_changeset(%User{}, params)
+
+      refute changeset.valid?
+    end
+
     test "it blocks blacklisted email domains" do
       clear_config([User, :email_blacklist], ["trolling.world"])
 
@@ -639,6 +657,11 @@ defmodule Pleroma.UserTest do
       changeset = User.register_changeset(%User{}, params)
       refute changeset.valid?
 
+      # Block with case-insensitive match
+      params = Map.put(@full_user_data, :email, "troll@TrOlLing.wOrld")
+      changeset = User.register_changeset(%User{}, params)
+      refute changeset.valid?
+
       # Block with subdomain match
       params = Map.put(@full_user_data, :email, "troll@gnomes.trolling.world")
       changeset = User.register_changeset(%User{}, params)