diff --git a/lib/peri.ex b/lib/peri.ex
index 0a0832e..8ba4ca7 100644
--- a/lib/peri.ex
+++ b/lib/peri.ex
@@ -129,7 +129,7 @@ defmodule Peri do
       Peri.validate(schema, invalid_data)
       # => {:error, [email: "is required"]}
   """
-  def validate(schema, data) when is_map(schema) and is_map(data) do
+  def validate(schema, data) when is_enumerable(schema) and is_enumerable(data) do
     data = filter_data(schema, data)
 
     case traverse_schema(schema, data) do
@@ -151,30 +151,44 @@ defmodule Peri do
     end
   end
 
-  defp filter_data(schema, data, acc \\ %{}) do
+  defp filter_data(schema, data) do
+    acc = if is_map(schema), do: %{}, else: []
+
     Enum.reduce(schema, acc, fn {key, type}, acc ->
       string_key = to_string(key)
-      original_key = if Map.has_key?(data, string_key), do: string_key, else: key
-      value = Map.get(data, original_key)
+      value = get_enumerable_value(data, key)
+      original_key = if enumerable_has_key?(data, key), do: key, else: string_key
 
       cond do
-        not (Map.has_key?(data, key) or Map.has_key?(data, string_key)) ->
+        is_enumerable(data) and not enumerable_has_key?(data, key) ->
           acc
 
-        is_map(value) and is_map(type) ->
+        is_enumerable(value) and is_enumerable(type) ->
           nested_filtered_value = filter_data(type, value)
-          Map.put(acc, original_key, nested_filtered_value)
+          put_in(acc[original_key], nested_filtered_value)
 
         true ->
-          Map.put(acc, original_key, value)
+          put_in(acc[original_key], value)
       end
     end)
+    |> then(fn
+      %{} = data -> data
+      data when is_list(data) -> Enum.reverse(data)
+    end)
+  end
+
+  defp enumerable_has_key?(data, key) when is_map(data) do
+    Map.has_key?(data, key) or Map.has_key?(data, Atom.to_string(key))
+  end
+
+  defp enumerable_has_key?(data, key) when is_list(data) do
+    Keyword.has_key?(data, key)
   end
 
   @doc false
   defp traverse_schema(schema, data, path \\ []) do
     Enum.reduce(schema, {[], path}, fn {key, type}, {errors, path} ->
-      value = Map.get(data, key) || Map.get(data, to_string(key))
+      value = get_enumerable_value(data, key)
 
       case validate_field(value, type) do
         :ok ->
@@ -196,6 +210,13 @@ defmodule Peri do
     end)
   end
 
+  defp get_enumerable_value(enum, key) do
+    case Access.get(enum, key) do
+      nil when is_map(enum) -> Map.get(enum, Atom.to_string(key))
+      val -> val
+    end
+  end
+
   defp update_error_paths(%Peri.Error{path: path, errors: nil} = error, new_path) do
     %Peri.Error{error | path: new_path ++ path}
   end
@@ -313,7 +334,7 @@ defmodule Peri do
     end)
   end
 
-  defp validate_field(data, schema) when is_map(data) do
+  defp validate_field(data, schema) when is_enumerable(data) do
     case traverse_schema(schema, data) do
       {[], _path} -> :ok
       {errors, _path} -> {:error, errors}
diff --git a/mix.exs b/mix.exs
index 0605e2a..69e5205 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule Peri.MixProject do
   use Mix.Project
 
-  @version "0.2.1"
+  @version "0.2.2"
   @source_url "https://github.com/zoedsoupe/peri"
 
   def project do
diff --git a/test/peri_test.exs b/test/peri_test.exs
index 69b2fc0..0def325 100644
--- a/test/peri_test.exs
+++ b/test/peri_test.exs
@@ -659,4 +659,288 @@ defmodule PeriTest do
                 ]}
     end
   end
+
+  defschema(:simple_keyword, [
+    {:name, :string},
+    {:age, :integer},
+    {:email, {:required, :string}}
+  ])
+
+  defschema(:nested_keyword, [
+    {:user,
+     [
+       {:name, :string},
+       {:profile,
+        [
+          {:age, {:required, :integer}},
+          {:email, {:required, :string}}
+        ]}
+     ]}
+  ])
+
+  defschema(:optional_fields_keyword, [
+    {:name, :string},
+    {:age, {:required, :integer}},
+    {:email, {:required, :string}},
+    {:phone, :string}
+  ])
+
+  describe "simple keyword list schema validation" do
+    test "validates simple keyword list schema with valid data" do
+      data = [name: "John", age: 30, email: "john@example.com"]
+      assert {:ok, ^data} = simple_keyword(data)
+    end
+
+    test "validates simple keyword list schema with missing required field" do
+      data = [name: "John", age: 30]
+
+      assert {:error, [%Peri.Error{path: [:email], message: "is required"}]} =
+               simple_keyword(data)
+    end
+
+    test "validates simple keyword list schema with invalid field type" do
+      data = [name: "John", age: "thirty", email: "john@example.com"]
+
+      assert {:error,
+              [
+                %Peri.Error{
+                  path: [:age],
+                  message: "expected type of integer received \"thirty\" value"
+                }
+              ]} =
+               simple_keyword(data)
+    end
+  end
+
+  describe "nested keyword list schema validation" do
+    test "validates nested keyword list schema with valid data" do
+      data = [user: [name: "Jane", profile: [age: 25, email: "jane@example.com"]]]
+      assert {:ok, ^data} = nested_keyword(data)
+    end
+
+    test "validates nested keyword list schema with invalid data" do
+      data = [user: [name: "Jane", profile: [age: "twenty-five", email: "jane@example.com"]]]
+
+      assert {
+               :error,
+               [
+                 %Peri.Error{
+                   message: nil,
+                   path: [:user],
+                   content: nil,
+                   errors: [
+                     %Peri.Error{
+                       path: [:user, :profile],
+                       key: :profile,
+                       content: nil,
+                       message: nil,
+                       errors: [
+                         %Peri.Error{
+                           path: [:user, :profile, :age],
+                           key: :age,
+                           content: [expected: :integer, actual: "\"twenty-five\""],
+                           message: "expected type of integer received \"twenty-five\" value",
+                           errors: nil
+                         }
+                       ]
+                     }
+                   ],
+                   key: :user
+                 }
+               ]
+             } = nested_keyword(data)
+    end
+
+    test "validates nested keyword list schema with missing required field" do
+      data = [user: [name: "Jane", profile: [age: 25]]]
+
+      assert {
+               :error,
+               [
+                 %Peri.Error{
+                   message: nil,
+                   path: [:user],
+                   content: nil,
+                   errors: [
+                     %Peri.Error{
+                       path: [:user, :profile],
+                       key: :profile,
+                       content: nil,
+                       message: nil,
+                       errors: [
+                         %Peri.Error{
+                           path: [:user, :profile, :email],
+                           key: :email,
+                           content: [],
+                           message: "is required",
+                           errors: nil
+                         }
+                       ]
+                     }
+                   ],
+                   key: :user
+                 }
+               ]
+             } =
+               nested_keyword(data)
+    end
+  end
+
+  describe "optional fields keyword list validation" do
+    test "validates keyword list schema with optional fields" do
+      data = [name: "John", age: 30, email: "john@example.com"]
+      assert {:ok, ^data} = optional_fields_keyword(data)
+
+      data_with_optional = [name: "John", age: 30, email: "john@example.com", phone: "123-456"]
+      assert {:ok, ^data_with_optional} = optional_fields_keyword(data_with_optional)
+    end
+
+    test "validates keyword list schema with optional fields and invalid optional field type" do
+      data = [name: "John", age: 30, email: "john@example.com", phone: 123_456]
+
+      assert {:error,
+              [
+                %Peri.Error{
+                  path: [:phone],
+                  message: "expected type of string received 123456 value"
+                }
+              ]} =
+               optional_fields_keyword(data)
+    end
+  end
+
+  defschema(:mixed_schema, %{
+    user_info: [
+      avatar: %{
+        url: :string
+      },
+      username: {:required, :string},
+      role: {:required, {:enum, [:admin, :user]}}
+    ]
+  })
+
+  describe "mixed schema validation" do
+    test "validates mixed schema with valid data" do
+      data = %{
+        user_info: [
+          avatar: %{url: "http://example.com/avatar.jpg"},
+          username: "john_doe",
+          role: :admin
+        ]
+      }
+
+      assert {:ok, ^data} = mixed_schema(data)
+    end
+
+    test "validates mixed schema with missing required field" do
+      data = %{user_info: %{avatar: %{url: "http://example.com/avatar.jpg"}, role: :admin}}
+
+      assert {
+               :error,
+               [
+                 %Peri.Error{
+                   message: nil,
+                   path: [:user_info],
+                   content: nil,
+                   errors: [
+                     %Peri.Error{
+                       path: [:user_info, :username],
+                       key: :username,
+                       content: [],
+                       message: "is required",
+                       errors: nil
+                     }
+                   ],
+                   key: :user_info
+                 }
+               ]
+             } =
+               mixed_schema(data)
+    end
+
+    test "validates mixed schema with invalid enum value" do
+      data = %{
+        user_info: %{
+          avatar: %{url: "http://example.com/avatar.jpg"},
+          username: "john_doe",
+          role: :superuser
+        }
+      }
+
+      assert {
+               :error,
+               [
+                 %Peri.Error{
+                   message: nil,
+                   path: [:user_info],
+                   content: nil,
+                   errors: [
+                     %Peri.Error{
+                       path: [:user_info, :role],
+                       key: :role,
+                       content: [choices: "[:admin, :user]", actual: ":superuser"],
+                       message: "expected one of [:admin, :user] received :superuser",
+                       errors: nil
+                     }
+                   ],
+                   key: :user_info
+                 }
+               ]
+             } = mixed_schema(data)
+    end
+
+    test "validates mixed schema with invalid field type" do
+      data = %{user_info: %{avatar: %{url: 12345}, username: "john_doe", role: :admin}}
+
+      assert {
+               :error,
+               [
+                 %Peri.Error{
+                   message: nil,
+                   path: [:user_info],
+                   content: nil,
+                   errors: [
+                     %Peri.Error{
+                       path: [:user_info, :avatar],
+                       key: :avatar,
+                       content: nil,
+                       message: nil,
+                       errors: [
+                         %Peri.Error{
+                           path: [:user_info, :avatar, :url],
+                           key: :url,
+                           content: [expected: :string, actual: "12345"],
+                           message: "expected type of string received 12345 value",
+                           errors: nil
+                         }
+                       ]
+                     }
+                   ],
+                   key: :user_info
+                 }
+               ]
+             } = mixed_schema(data)
+    end
+
+    test "validates mixed schema with extra fields" do
+      data = %{
+        user_info: %{
+          avatar: %{url: "http://example.com/avatar.jpg", size: "large"},
+          username: "john_doe",
+          role: :admin,
+          extra_field: "extra"
+        }
+      }
+
+      expected_data = %{
+        user_info: [
+          avatar: %{url: "http://example.com/avatar.jpg"},
+          username: "john_doe",
+          role: :admin
+        ]
+      }
+
+      assert {:ok, ^expected_data} = mixed_schema(data)
+    end
+  end
 end