VERSION                |  2 +-
 doc/news.rst           |  7 +++++++
 pyderasn.py            | 10 ++++++++--
 tests/test_pyderasn.py |  3 +++

diff --git a/VERSION b/VERSION
index 2c858ab6c54dddd5d5d3f908545751c6fc591a0d5740edad717a56e61e03b2b7..24b3f98e572ed79b336550ac9fc62a86d9a902822eacf155ba85853af320aa89 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.0
+2.1
diff --git a/doc/news.rst b/doc/news.rst
index 8fc3928f53029d33f9bae37589c2cd7ab6035b54c45213ff99aa14fdf14f168b..5d74df9c91cb3f042bb4f6e6930fdc9505d552214f30ce1c4e0d4fdb0779f548 100644
--- a/doc/news.rst
+++ b/doc/news.rst
@@ -1,6 +1,13 @@
 News
 ====
 
+.. _release2.1:
+
+2.1
+---
+* Fixed invalid offset calculation when dealing with DEFINED BY objects
+  having explicit tags
+
 .. _release2.0:
 
 2.0
diff --git a/pyderasn.py b/pyderasn.py
index 0b05723e0089e56bea0ea3abdad0153aaf6822d426a6493c20a2311ad5b5ac60..b0b38d530c9995618de7a29dcc54aed7359330c0bb7ba57ccf09ece0d9d16c3f 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -3875,7 +3875,10 @@                             decode_path_defby(defined_by),
                         )
                         defined_value, defined_tail = defined_spec.decode(
                             memoryview(bytes(_value)),
-                            sub_offset + value.tlen + value.llen,
+                            sub_offset + (
+                                (value.tlen + value.llen + value.expl_tlen + value.expl_llen)
+                                if value.expled else (value.tlen + value.llen)
+                            ),
                             leavemm=True,
                             decode_path=sub_sub_decode_path,
                             ctx=ctx,
@@ -3891,7 +3894,10 @@                         _value.defined = (defined_by, defined_value)
                 else:
                     defined_value, defined_tail = defined_spec.decode(
                         memoryview(bytes(value)),
-                        sub_offset + value.tlen + value.llen,
+                        sub_offset + (
+                            (value.tlen + value.llen + value.expl_tlen + value.expl_llen)
+                            if value.expled else (value.tlen + value.llen)
+                        ),
                         leavemm=True,
                         decode_path=sub_decode_path + (decode_path_defby(defined_by),),
                         ctx=ctx,
diff --git a/tests/test_pyderasn.py b/tests/test_pyderasn.py
index 557db850df139c91eb5e78af63975a511e7b10ddbcb7b29662e7da49780b3e40..69c8a3925da522f061caa970e02976fa28bcc04788e9e51454aa6505262d45e9 100644
--- a/tests/test_pyderasn.py
+++ b/tests/test_pyderasn.py
@@ -5003,6 +5003,9 @@         )
         self.assertIsNotNone(seq_integered["value"].defined)
         self.assertEqual(seq_integered["value"].defined[0], type_integered)
         self.assertEqual(seq_integered["value"].defined[1], Integer(123))
+        self.assertTrue(seq_integered_raw[
+            seq_integered["value"].defined[1].offset:
+        ].startswith(Integer(123).encode()))
 
         seq_sequenced, _ = Seq().decode(
             seq_sequenced_raw,