diff --git a/conda_devenv/devenv.py b/conda_devenv/devenv.py
index a89cf89..aad9646 100644
--- a/conda_devenv/devenv.py
+++ b/conda_devenv/devenv.py
@@ -7,16 +7,17 @@ import sys
 import six
 
 
-def render_jinja(contents, filename):
+def render_jinja(contents, filename, is_included):
     import jinja2
     import sys
     import platform
 
     jinja_dict = {
-        "root": os.path.dirname(os.path.abspath(filename)),
+        "is_included": is_included,
         "os": os,
-        "sys": sys,
         "platform": platform,
+        "root": os.path.dirname(os.path.abspath(filename)),
+        "sys": sys,
     }
 
     return jinja2.Template(contents).render(**jinja_dict)
@@ -49,7 +50,7 @@ def handle_includes(root_filename, root_yaml):
                         filename=filename
                     ))
             with open(included_filename, "r") as f:
-                jinja_contents = render_jinja(f.read(), included_filename)
+                jinja_contents = render_jinja(f.read(), included_filename, is_included=True)
             included_yaml_dict = yaml.safe_load(jinja_contents)
             if included_yaml_dict is None:
                 raise ValueError("The file '{included_filename}' which was"
@@ -182,7 +183,7 @@ def merge_dependencies_version_specifications(yaml_dict, key_to_merge):
 def load_yaml_dict(filename):
     with open(filename, "r") as f:
         contents = f.read()
-    rendered_contents = render_jinja(contents, filename)
+    rendered_contents = render_jinja(contents, filename, is_included=False)
 
     import yaml
     root_yaml = yaml.load(rendered_contents)

diff --git a/tests/test_include.py b/tests/test_include.py
index f3eb7fc..308206d 100644
--- a/tests/test_include.py
+++ b/tests/test_include.py
@@ -7,7 +7,7 @@ from conda_devenv.devenv import handle_includes, render_jinja
 
 def obtain_yaml_dicts(root_yaml_filename):
     contents = open(root_yaml_filename, "r").read()
-    contents = render_jinja(contents, filename=root_yaml_filename)
+    contents = render_jinja(contents, filename=root_yaml_filename, is_included=False)
     root_yaml = yaml.load(contents)
     dicts = handle_includes(root_yaml_filename, root_yaml).values()
     dicts = list(dicts)
diff --git a/tests/test_jinja.py b/tests/test_jinja.py
index 551305e..b3ff3d8 100644
--- a/tests/test_jinja.py
+++ b/tests/test_jinja.py
@@ -10,7 +10,11 @@ from conda_devenv.devenv import render_jinja
 
 
 def test_jinja_root():
-    assert render_jinja("{{root}}", filename="path/to/file") == os.path.abspath("path/to")
+    assert render_jinja(
+        "{{root}}",
+        filename="path/to/file",
+        is_included=False,
+    ) == os.path.abspath("path/to")
 
 
 def test_jinja_os(monkeypatch):
@@ -22,13 +26,13 @@ def test_jinja_os(monkeypatch):
         {%- endif %}
     """).strip()
 
-    assert render_jinja(template, filename="") == "variable is not set"
+    assert render_jinja(template, filename="", is_included=False) == "variable is not set"
 
     monkeypatch.setenv('ENV_VARIABLE', '1')
-    assert render_jinja(template, filename="") == "variable is set"
+    assert render_jinja(template, filename="", is_included=False) == "variable is set"
 
     monkeypatch.setenv('ENV_VARIABLE', '2')
-    assert render_jinja(template, filename="") == "variable is not set"
+    assert render_jinja(template, filename="", is_included=False) == "variable is not set"
 
 
 def test_jinja_sys(monkeypatch):
@@ -43,27 +47,27 @@ def test_jinja_sys(monkeypatch):
     """).strip()
 
     monkeypatch.setattr(sys, 'platform', 'linux')
-    assert render_jinja(template, filename="") == "linux!"
+    assert render_jinja(template, filename="", is_included=False) == "linux!"
 
     monkeypatch.setattr(sys, 'platform', 'windows')
-    assert render_jinja(template, filename="") == "windows!"
+    assert render_jinja(template, filename="", is_included=False) == "windows!"
 
     monkeypatch.setattr(sys, 'platform', 'darwin')
-    assert render_jinja(template, filename="") == "others!"
+    assert render_jinja(template, filename="", is_included=False) == "others!"
 
 
 def test_jinja_platform(monkeypatch):
     template = "{{ platform.python_revision() }}"
-    assert render_jinja(template, filename="") == platform.python_revision()
+    assert render_jinja(template, filename="", is_included=False) == platform.python_revision()
 
 
 def test_jinja_invalid_template():
-    # TODO: change this to pytest's nicer syntax: with pytest.raises()
-    try:
-        render_jinja(textwrap.dedent("""\
+    with pytest.raises(jinja2.exceptions.TemplateSyntaxError):
+        render_jinja(
+            textwrap.dedent("""\
                 {%- if os.environ['ENV_VARIABLE'] == '1' %}
                 {% %}
-            """), filename="")
-        pytest.fail("Should raise an exception")
-    except jinja2.exceptions.TemplateSyntaxError as e:
-        pass
+            """),
+            filename="",
+            is_included=False,
+        )
diff --git a/tests/test_load_yaml_dict.py b/tests/test_load_yaml_dict.py
index 43ed3d5..3c9d6eb 100644
--- a/tests/test_load_yaml_dict.py
+++ b/tests/test_load_yaml_dict.py
@@ -63,3 +63,34 @@ def test_get_env_name(mocker, tmpdir, cmd_line_name):
         assert name == 'foo'
     else:
         assert name == 'bar'
+
+
+def test_is_included_var(datadir):
+    import six
+    import textwrap
+    a_env_file = datadir / 'a.devenv.yml'
+    a_env_file.write_text(six.text_type(textwrap.dedent('''\
+        name: a
+        includes:
+          - {{root}}/b.devenv.yml
+        environment:
+          VARIABLE: value_a
+          IS_A_INCLUDED: {{is_included}}
+    ''')))
+    b_env_file = datadir / 'b.devenv.yml'
+    b_env_file.write_text(six.text_type(textwrap.dedent('''\
+        name: b
+        environment:
+          {% if not is_included %}
+          VARIABLE: value_b
+          {% endif %}
+          IS_B_INCLUDED: {{is_included}}
+    ''')))
+
+    conda_env, os_env = load_yaml_dict(str(a_env_file))
+    assert conda_env == {'name': 'a'}
+    assert os_env == {
+        'IS_A_INCLUDED': False,
+        'IS_B_INCLUDED': True,
+        'VARIABLE': 'value_a',
+    }

Add a way to identify if the current file is the "main" devenv file
tests/test_jinja.py::test_jinja_root tests/test_jinja.py::test_jinja_os tests/test_jinja.py::test_jinja_sys tests/test_jinja.py::test_jinja_platform tests/test_jinja.py::test_jinja_invalid_template
tests/test_load_yaml_dict.py::test_get_env_name[True] tests/test_load_yaml_dict.py::test_get_env_name[False]