diff --git a/instructor/anthropic_utils.py b/instructor/anthropic_utils.py
index 6bd75eee6..6aecd640c 100644
--- a/instructor/anthropic_utils.py
+++ b/instructor/anthropic_utils.py
@@ -1,9 +1,17 @@
+# type: ignore
 import re
-import xmltodict
 from pydantic import BaseModel
-import xml.etree.ElementTree as ET
 from typing import Type, Any, Dict, TypeVar
 
+
+try:
+    import xmltodict
+    import xml.etree.ElementTree as ET
+except ImportError:
+    import warnings
+warnings.warn("xmltodict and xml.etree.ElementTree modules not found. Please install them to proceed. `pip install xmltodict`", ImportWarning)
+
+
 T = TypeVar("T", bound=BaseModel)
 
 
diff --git a/instructor/function_calls.py b/instructor/function_calls.py
index 84a4da91b..d4fbf6dd2 100644
--- a/instructor/function_calls.py
+++ b/instructor/function_calls.py
@@ -2,14 +2,12 @@
 from docstring_parser import parse
 from functools import wraps
 from pydantic import BaseModel, create_model
-from instructor.exceptions import IncompleteOutputException
 from openai.types.chat import ChatCompletion
+from instructor.exceptions import IncompleteOutputException
 from instructor.mode import Mode
 from instructor.utils import extract_json_from_codeblock
 import logging
-import importlib
 
-from .anthropic_utils import json_to_xml, extract_xml, xml_to_model
 
 T = TypeVar("T")
 
@@ -63,6 +61,7 @@ def openai_schema(cls) -> Dict[str, Any]:
     @classmethod
     @property
     def anthropic_schema(cls) -> str:
+        from instructor.anthropic_utils import json_to_xml, extract_xml, xml_to_model
         return json_to_xml(cls)
 
     @classmethod
@@ -87,10 +86,7 @@ def from_response(
         """
         if mode == Mode.ANTHROPIC_TOOLS:
             try:
-                assert isinstance(
-                    completion,
-                    importlib.import_module("anthropic.types.message").Message,
-                )
+                from instructor.anthropic_utils import extract_xml, xml_to_model
             except ImportError as err:
                 raise ImportError("Please 'pip install anthropic' package to proceed.") from err
             assert hasattr(completion, "content")
diff --git a/pyproject.toml b/pyproject.toml
index 50d4c7551..bf7769f50 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "instructor"
-version = "0.6.5"
+version = "0.6.6"
 description = "structured outputs for llm"
 authors = ["Jason Liu <jason@jxnl.co>"]
 license = "MIT"