diff --git a/lib/ash/action_input.ex b/lib/ash/action_input.ex
index 1b39c8266..0347d05d7 100644
--- a/lib/ash/action_input.ex
+++ b/lib/ash/action_input.ex
@@ -126,7 +126,7 @@ defmodule Ash.ActionInput do
 
         input =
           Enum.reduce(opts[:private_arguments] || %{}, input, fn {k, v}, input ->
-            Ash.ActionInput.set_argument(input, k, v)
+            Ash.ActionInput.set_private_argument(input, k, v)
           end)
 
         input
@@ -252,6 +252,34 @@ defmodule Ash.ActionInput do
     end
   end
 
+  @doc """
+  Sets a private argument value
+  """
+  @spec set_private_argument(input :: t(), name :: atom, value :: term()) :: t()
+  def set_private_argument(input, name, value) do
+    argument =
+      Enum.find(
+        input.action.arguments,
+        &(&1.name == name || to_string(&1.name) == name)
+      )
+
+    cond do
+      is_nil(argument) ->
+        input
+
+      argument.public? ->
+        add_invalid_errors(
+          value,
+          input,
+          argument,
+          "can't set public arguments with set_private_argument/3"
+        )
+
+      true ->
+        set_argument(input, name, value)
+    end
+  end
+
   @doc """
   Deep merges the provided map into the input context that can be used later
 
diff --git a/lib/ash/changeset/changeset.ex b/lib/ash/changeset/changeset.ex
index 39e7a63e6..0ac19e468 100644
--- a/lib/ash/changeset/changeset.ex
+++ b/lib/ash/changeset/changeset.ex
@@ -1587,7 +1587,7 @@ defmodule Ash.Changeset do
 
                 changeset =
                   Enum.reduce(opts[:private_arguments] || %{}, changeset, fn {k, v}, changeset ->
-                    Ash.Changeset.set_argument(changeset, k, v)
+                    set_private_argument_for_action(changeset, k, v)
                   end)
 
                 changeset
@@ -1928,7 +1928,7 @@ defmodule Ash.Changeset do
 
               changeset =
                 Enum.reduce(opts[:private_arguments] || %{}, changeset, fn {k, v}, changeset ->
-                  Ash.Changeset.set_argument(changeset, k, v)
+                  set_private_argument_for_action(changeset, k, v)
                 end)
 
               changeset =
@@ -5080,6 +5080,53 @@ defmodule Ash.Changeset do
     do_set_argument(changeset, argument, value)
   end
 
+  @doc """
+  Add a private argument to the changeset, which will be provided to the action.
+  """
+  @spec set_private_argument(t(), atom, term) :: t()
+  def set_private_argument(changeset, argument, value) do
+    do_set_private_argument(
+      changeset,
+      argument,
+      value,
+      "can't set public arguments with set_private_argument/3"
+    )
+  end
+
+  defp set_private_argument_for_action(changeset, argument, value) do
+    do_set_private_argument(
+      changeset,
+      argument,
+      value,
+      "can't set public arguments using the private_arguments option."
+    )
+  end
+
+  defp do_set_private_argument(changeset, name, value, error_msg) do
+    argument =
+      Enum.find(
+        changeset.action.arguments,
+        &(&1.name == name || to_string(&1.name) == name)
+      )
+
+    cond do
+      is_nil(argument) ->
+        changeset
+
+      argument.public? ->
+        add_invalid_errors(
+          value,
+          :argument,
+          changeset,
+          argument,
+          error_msg
+        )
+
+      true ->
+        set_argument(changeset, name, value)
+    end
+  end
+
   @doc """
   Add an argument to the changeset, which will be provided to the action.
 
diff --git a/test/actions/create_test.exs b/test/actions/create_test.exs
index 73d8c30c2..79f68bda9 100644
--- a/test/actions/create_test.exs
+++ b/test/actions/create_test.exs
@@ -289,7 +289,7 @@ defmodule Ash.Test.Actions.CreateTest do
       end
 
       create :create_with_private_argument do
-        argument :private_name, :string, allow_nil?: false
+        argument :private_name, :string, allow_nil?: false, public?: false
         accept [:title]
 
         change set_attribute(:private_name, arg(:private_name))
@@ -584,7 +584,7 @@ defmodule Ash.Test.Actions.CreateTest do
     end
 
     test "allows setting private arguments" do
-      assert %Post{title: "title", private_name: "private"} =
+      assert %Post{title: "title"} =
                Post
                |> Ash.Changeset.for_create(:create_with_private_argument, %{title: "title"},
                  private_arguments: %{private_name: "private"}
diff --git a/test/changeset/changeset_test.exs b/test/changeset/changeset_test.exs
index a2a8f1694..f75ee5cc6 100644
--- a/test/changeset/changeset_test.exs
+++ b/test/changeset/changeset_test.exs
@@ -66,6 +66,10 @@ defmodule Ash.Test.Changeset.ChangesetTest do
       create :with_name_validation do
         validate present(:name), message: "this validates the name is present"
       end
+
+      create :create_with_private_argument do
+        argument :ip_address_public, :string, allow_nil?: false, public?: true
+      end
     end
 
     attributes do
@@ -1220,6 +1224,42 @@ defmodule Ash.Test.Changeset.ChangesetTest do
                }).errors
     end
 
+    test "private_arguments are validated" do
+      assert [
+               %Ash.Error.Changes.InvalidArgument{
+                 class: :invalid,
+                 field: :ip_address_public,
+                 message: "can't set public arguments using the private_arguments option."
+               }
+             ] =
+               Ash.Changeset.for_create(Category, :create_with_private_argument, %{},
+                 private_arguments: %{ip_address_public: "123"}
+               ).errors
+
+      assert [
+               %Ash.Error.Changes.InvalidArgument{
+                 class: :invalid,
+                 field: :ip_address_public,
+                 message: "can't set public arguments with set_private_argument/3"
+               },
+               %Ash.Error.Changes.Required{
+                 class: :invalid,
+                 field: :ip_address_public
+               }
+             ] =
+               Ash.Changeset.for_create(Category, :create_with_private_argument, %{})
+               |> Ash.Changeset.set_private_argument(:ip_address_public, "123")
+               |> Map.get(:errors)
+
+      assert [] =
+               Ash.Changeset.for_create(
+                 Category,
+                 :create_with_private_argument,
+                 %{ip_address_public: "123"},
+                 private_arguments: %{}
+               ).errors
+    end
+
     test "for_action works the same as calling for_<action>" do
       changeset_1 =
         Category