diff --git a/tests/unit/providers/configuration/conftest.py b/tests/unit/providers/configuration/conftest.py
index d4f1ef0a..9f473790 100644
--- a/tests/unit/providers/configuration/conftest.py
+++ b/tests/unit/providers/configuration/conftest.py
@@ -106,7 +106,9 @@ def environment_variables():
     os.environ["CONFIG_TEST_ENV"] = "test-value"
     os.environ["CONFIG_TEST_PATH"] = "test-path"
     os.environ["DEFINED"] = "defined"
+    os.environ["CONFIG_INT"] = "42"
     yield
     os.environ.pop("CONFIG_TEST_ENV", None)
     os.environ.pop("CONFIG_TEST_PATH", None)
     os.environ.pop("DEFINED", None)
+    os.environ.pop("CONFIG_INT", None)
diff --git a/tests/unit/providers/configuration/test_from_env_py2_py3.py b/tests/unit/providers/configuration/test_from_env_py2_py3.py
index 4c9a70db..24c4e914 100644
--- a/tests/unit/providers/configuration/test_from_env_py2_py3.py
+++ b/tests/unit/providers/configuration/test_from_env_py2_py3.py
@@ -31,6 +31,42 @@ def test_option_default_none(config):
     assert config.option() is None
 
 
+def test_as_(config):
+    config.from_env("CONFIG_INT", as_=int)
+    assert config() == 42
+    assert isinstance(config(), int)
+
+
+def test_as__default(config):
+    config.from_env("UNDEFINED", as_=int, default="33")
+    assert config() == 33
+    assert isinstance(config(), int)
+
+
+def test_as__undefined_required(config):
+    with raises(ValueError):
+        config.from_env("UNDEFINED", as_=int, required=True)
+    assert config() == {}
+
+
+def test_option_as_(config):
+    config.option.from_env("CONFIG_INT", as_=int)
+    assert config.option() == 42
+    assert isinstance(config.option(), int)
+
+
+def test_option_as__default(config):
+    config.option.from_env("UNDEFINED", as_=int, default="33")
+    assert config.option() == 33
+    assert isinstance(config.option(), int)
+
+
+def test_option_as__undefined_required(config):
+    with raises(ValueError):
+        config.option.from_env("UNDEFINED", as_=int, required=True)
+    assert config.option() is None
+
+
 @mark.parametrize("config_type", ["strict"])
 def test_undefined_in_strict_mode(config):
     with raises(ValueError):