diff --git a/dataconf/exceptions.py b/dataconf/exceptions.py
index 99dfae0..45b4a94 100644
--- a/dataconf/exceptions.py
+++ b/dataconf/exceptions.py
@@ -34,6 +34,12 @@ class EnvListOrderException(Exception):
     pass
 
 
+class EnvListFormatException(Exception):
+    """Format exception."""
+
+    pass
+
+
 class ParseException(Exception):
     """Parsing exception."""
 
diff --git a/dataconf/utils.py b/dataconf/utils.py
index 164478a..fbdd3fa 100644
--- a/dataconf/utils.py
+++ b/dataconf/utils.py
@@ -17,7 +17,7 @@
 from typing import Type
 from typing import Union
 
-from dataconf.exceptions import AmbiguousSubclassException
+from dataconf.exceptions import AmbiguousSubclassException, EnvListFormatException
 from dataconf.exceptions import EnvListOrderException
 from dataconf.exceptions import MalformedConfigException
 from dataconf.exceptions import MissingTypeException
@@ -333,6 +333,8 @@ def set_lens(p, focus, v):
         if len(p) == 1:
             # []x
             if isinstance(focus, list):
+                if not isinstance(p[0], int):
+                    raise EnvListFormatException
                 if p[0] != len(focus):
                     raise EnvListOrderException
                 focus.append(v)
@@ -346,9 +348,8 @@ def set_lens(p, focus, v):
             if p[0] not in focus:
                 # []{x}
                 if isinstance(focus, list):
-                    if p[0] != len(focus):
-                        raise EnvListOrderException
-                    focus.append({})
+                    if p[0] == len(focus):
+                        focus.append({})
                 # {}{x}
                 else:
                     focus[p[0]] = {}
diff --git a/tests/test_env_vars.py b/tests/test_env_vars.py
index fa6dd57..bebc7c3 100644
--- a/tests/test_env_vars.py
+++ b/tests/test_env_vars.py
@@ -1,4 +1,4 @@
-from dataconf.exceptions import EnvListOrderException
+from dataconf.exceptions import EnvListFormatException, EnvListOrderException
 from dataconf.exceptions import ParseException
 from dataconf.utils import __env_vars_parse as env_vars_parse
 import pytest
@@ -65,6 +65,37 @@ def test_ls_order(self) -> None:
         with pytest.raises(EnvListOrderException):
             env_vars_parse("P", env)
 
+    def test_ls_obj(self) -> None:
+        env = {
+            "P_A_0__A": "1",
+            "P_A_1__A": "2",
+        }
+        assert env_vars_parse("P", env) == dict(a=[dict(a="1"), dict(a="2")])
+
+        env = {
+            "P_A_0__A": "1",
+            "P_A_0__B": "2",
+        }
+        assert env_vars_parse("P", env) == dict(a=[dict(a="1", b="2")])
+
+        env = {
+            "P_A_0__A": "1",
+            "P_A_0__B": "2",
+            "P_A_1__A": "3",
+            "P_A_1__B": "4",
+        }
+        assert env_vars_parse("P", env) == dict(
+            a=[dict(a="1", b="2"), dict(a="3", b="4")]
+        )
+
+    def test_ls_wrong_obj(self) -> None:
+        env = {
+            "P_A_0_A": "1",
+            "P_A_1_A": "2",
+        }
+        with pytest.raises(EnvListFormatException):
+            env_vars_parse("P", env)
+
     def test_number(self) -> None:
         env = {
             "A": "1",