diff --git a/chanfig/utils.py b/chanfig/utils.py
index 6f1f86ba..8ae72d1b 100644
--- a/chanfig/utils.py
+++ b/chanfig/utils.py
@@ -17,6 +17,7 @@
 
 from __future__ import annotations
 
+import os
 import sys
 from argparse import ArgumentTypeError
 from collections.abc import Callable, Mapping, Sequence
@@ -31,6 +32,8 @@
 import typing_extensions
 from typing_extensions import get_args, get_origin
 from yaml import SafeDumper, SafeLoader
+from yaml.constructor import ConstructorError
+from yaml.nodes import ScalarNode, SequenceNode
 
 try:  # python 3.10+
     from types import UnionType  # type: ignore[attr-defined] # pylint: disable=C0412
@@ -293,18 +296,43 @@ def increase_indent(self, flow: bool = False, indentless: bool = False):  # pyli
         return super().increase_indent(flow, indentless)
 
 
-class YamlLoader(SafeLoader):  # pylint: disable=R0901,R0903
+class YamlLoader(SafeLoader):
     r"""
     YAML Loader for Config.
     """
 
-
-try:
-    from yamlinclude import YamlIncludeConstructor
-
-    YamlIncludeConstructor.add_to_loader_class(loader_class=YamlLoader, relative=True)
-except ImportError:
-    pass
+    def __init__(self, stream):
+        super().__init__(stream)
+        self._root = os.path.abspath(os.path.dirname(stream.name)) if hasattr(stream, "name") else os.getcwd()
+        self.add_constructor("!include", self._include)
+        self.add_constructor("!includes", self._includes)
+        self.add_constructor("!env", self._env)
+
+    @staticmethod
+    def _include(loader: YamlLoader, node):
+        relative_path = loader.construct_scalar(node)
+        include_path = os.path.join(loader._root, relative_path)
+
+        if not os.path.exists(include_path):
+            raise FileNotFoundError(f"Included file not found: {include_path}")
+        from .functional import load
+
+        return load(include_path)
+
+    @staticmethod
+    def _includes(loader: YamlLoader, node):
+        if not isinstance(node, SequenceNode):
+            raise ConstructorError(None, None, f"!includes tag expects a sequence, got {node.id}", node.start_mark)
+        files = loader.construct_sequence(node)
+        return [YamlLoader._include(loader, ScalarNode("tag:yaml.org,2002:str", file)) for file in files]
+
+    @staticmethod
+    def _env(loader: YamlLoader, node):
+        env_var = loader.construct_scalar(node)
+        value = os.getenv(env_var)
+        if value is None:
+            raise ValueError(f"Environment variable '{env_var}' not set.")
+        return value
 
 
 Null = NULL()
diff --git a/pyproject.toml b/pyproject.toml
index 80e477c0..878bc197 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,9 +47,6 @@ dependencies = [
   "pyyaml",
   "typing-extensions",
 ]
-optional-dependencies.include = [
-  "pyyaml-include",
-]
 urls.documentation = "https://chanfig.danling.org"
 urls.homepage = "https://chanfig.danling.org"
 urls.repository = "https://github.com/ZhiyuanChen/CHANfiG"
diff --git a/tests/child.yaml b/tests/child.yaml
new file mode 100644
index 00000000..a5b5967e
--- /dev/null
+++ b/tests/child.yaml
@@ -0,0 +1,3 @@
+optim:
+  name: "adam"
+  lr: 0.01
\ No newline at end of file
diff --git a/tests/model.yaml b/tests/model.yaml
new file mode 100644
index 00000000..2136fdcc
--- /dev/null
+++ b/tests/model.yaml
@@ -0,0 +1,2 @@
+num_channels: 512
+multiple: 256
\ No newline at end of file
diff --git a/tests/parent.yaml b/tests/parent.yaml
new file mode 100644
index 00000000..6c36c74e
--- /dev/null
+++ b/tests/parent.yaml
@@ -0,0 +1,2 @@
+model: !include model.yaml
+port: 80
\ No newline at end of file
diff --git a/tests/test_misc.py b/tests/test_misc.py
index 9b83f009..e3c2f7d4 100644
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -36,3 +36,9 @@ def test_interpolate_eval(self):
         assert config.data.imagenet.data_dirs[2] == "localhost:80/X-C"
         assert config.model.num_heads == config.model.num_channels // 64
         assert config.model.num_hidden_size == config.model.num_channels // 64 * config.model.multiple
+
+    def test_include(self):
+        config = chanfig.load("tests/parent.yaml")
+        model = chanfig.load("tests/model.yaml")
+        assert config.model == model
+        assert config.port == 80