diff --git a/lib/chat_models/chat_anthropic.ex b/lib/chat_models/chat_anthropic.ex
index 4d800bc..dd7d6a4 100644
--- a/lib/chat_models/chat_anthropic.ex
+++ b/lib/chat_models/chat_anthropic.ex
@@ -367,7 +367,7 @@ defmodule LangChain.ChatModels.ChatAnthropic do
         end
 
       {:ok, %Req.Response{status: 529}} ->
-        {:error, LangChainError.exception(type: "overloaded", message: "Overloaded")}
+        {:error, LangChainError.exception(type: "overloaded_error", message: "Overloaded")}
 
       {:error, %Req.TransportError{reason: :timeout} = err} ->
         {:error,
@@ -415,7 +415,9 @@ defmodule LangChain.ChatModels.ChatAnthropic do
 
         data
 
-      {:error, %LangChainError{} = error} ->
+        # The error tuple was successfully received from the API. Unwrap it and
+        # return it as an error.
+      {:ok, {:error, %LangChainError{} = error}} ->
         {:error, error}
 
       {:error, %Req.TransportError{reason: :timeout} = err} ->
diff --git a/test/chains/llm_chain_test.exs b/test/chains/llm_chain_test.exs
index 63b6269..e0b4092 100644
--- a/test/chains/llm_chain_test.exs
+++ b/test/chains/llm_chain_test.exs
@@ -6,6 +6,7 @@ defmodule LangChain.Chains.LLMChainTest do
 
   import LangChain.Fixtures
   alias LangChain.ChatModels.ChatOpenAI
+  alias LangChain.ChatModels.ChatAnthropic
   alias LangChain.Chains.LLMChain
   alias LangChain.PromptTemplate
   alias LangChain.Function
@@ -17,6 +18,8 @@ defmodule LangChain.Chains.LLMChainTest do
   alias LangChain.LangChainError
   alias LangChain.MessageProcessors.JsonProcessor
 
+  @anthropic_test_model "claude-3-opus-20240229"
+
   setup do
     {:ok, chat} = ChatOpenAI.new(%{temperature: 0})
 
@@ -956,6 +959,7 @@ defmodule LangChain.Chains.LLMChainTest do
         |> LLMChain.run()
 
       assert reason.type == nil
+
       assert reason.message ==
                "Invalid 'messages': empty array. Expected an array with minimum length 1, but got an empty array instead."
     end
@@ -971,6 +975,7 @@ defmodule LangChain.Chains.LLMChainTest do
         |> LLMChain.run()
 
       assert reason.type == nil
+
       assert reason.message ==
                "Invalid 'messages': empty array. Expected an array with minimum length 1, but got an empty array instead."
     end
@@ -1032,6 +1037,24 @@ defmodule LangChain.Chains.LLMChainTest do
       assert_received {:function_called, "fly_regions"}
     end
 
+    test "returns error when receives overloaded_error from Anthropic" do
+      # Made NOT LIVE here
+      expect(ChatAnthropic, :call, fn _model, _prompt, _tools ->
+        # IO.puts "ChatAnthropic.call OVERLOAD USED!!!!"
+        {:error,
+         LangChainError.exception(type: "overloaded_error", message: "Overloaded (from test)")}
+      end)
+
+      model = ChatAnthropic.new!(%{stream: true, model: @anthropic_test_model})
+
+      assert {:error, _updated_chain, reason} =
+               LLMChain.new!(%{llm: model})
+               |> LLMChain.run()
+
+      assert reason.type == "overloaded_error"
+      assert reason.message == "Overloaded (from test)"
+    end
+
     test "errors when messages have PromptTemplates" do
       messages = [
         PromptTemplate.new!(%{
diff --git a/test/chat_models/chat_anthropic_test.exs b/test/chat_models/chat_anthropic_test.exs
index 9022b17..4ca60ff 100644
--- a/test/chat_models/chat_anthropic_test.exs
+++ b/test/chat_models/chat_anthropic_test.exs
@@ -555,6 +555,22 @@ defmodule LangChain.ChatModels.ChatAnthropicTest do
                "Received error from API: The security token included in the request is invalid."
     end
 
+    test "returns error tuple when receiving overloaded_error" do
+      # Made NOT LIVE here
+      expect(Req, :post, fn _req_struct, _opts ->
+        # IO.puts "REQ OVERLOAD USED!!!!"
+        {:ok,
+         {:error,
+          LangChainError.exception(type: "overloaded_error", message: "Overloaded (from test)")}}
+      end)
+
+      model = ChatAnthropic.new!(%{stream: true, model: @test_model})
+      assert {:error, reason} = ChatAnthropic.call(model, "prompt", [])
+
+      assert reason.type == "overloaded_error"
+      assert reason.message == "Overloaded (from test)"
+    end
+
     for api <- @apis do
       Module.put_attribute(__MODULE__, :tag, {:"live_#{api}", true})
       @tag live_call: true, live_api: api
diff --git a/test/test_helper.exs b/test/test_helper.exs
index 12ad4d2..d8a7987 100644
--- a/test/test_helper.exs
+++ b/test/test_helper.exs
@@ -13,6 +13,7 @@ Application.put_env(
 Mimic.copy(LangChain.Utils.BedrockStreamDecoder)
 Mimic.copy(LangChain.Utils.AwsEventstreamDecoder)
 
+Mimic.copy(Req)
 Mimic.copy(LangChain.ChatModels.ChatOpenAI)
 Mimic.copy(LangChain.ChatModels.ChatAnthropic)
 Mimic.copy(LangChain.ChatModels.ChatMistralAI)