diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 31e40db..0aab798 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -1,6 +1,11 @@
 Changelog
 =========
 
+v1.0.10 (2024-10-25)
+-------------------
+
+- migrate cluster group from "other" to "other 1" inside v8.1 upgrader
+
 v1.0.9 (2024-10-16)
 -------------------
 
diff --git a/src/antares/study/version/__about__.py b/src/antares/study/version/__about__.py
index 79c20b7..6500251 100644
--- a/src/antares/study/version/__about__.py
+++ b/src/antares/study/version/__about__.py
@@ -4,7 +4,7 @@
 
 # Standard project metadata
 
-__version__ = "1.0.9"
+__version__ = "1.0.10"
 __author__ = "RTE, Antares Web Team"
-__date__ = "2024-10-16"
+__date__ = "2024-10-25"
 __credits__ = "© Réseau de Transport de l’Électricité (RTE)"
diff --git a/src/antares/study/version/upgrade_app/upgrader_0801.py b/src/antares/study/version/upgrade_app/upgrader_0801.py
index 78e4d49..53db539 100644
--- a/src/antares/study/version/upgrade_app/upgrader_0801.py
+++ b/src/antares/study/version/upgrade_app/upgrader_0801.py
@@ -4,6 +4,8 @@
 from antares.study.version.model.study_version import StudyVersion
 
 from .upgrade_method import UpgradeMethod
+from antares.study.version.ini_writer import IniWriter
+from antares.study.version.ini_reader import IniReader
 
 
 class UpgradeTo0801(UpgradeMethod):
@@ -28,3 +30,13 @@ def upgrade(cls, study_dir: Path) -> None:
         data.to_ini_file(study_dir)
         study_dir.joinpath("input", "renewables", "clusters").mkdir(parents=True, exist_ok=True)
         study_dir.joinpath("input", "renewables", "series").mkdir(parents=True, exist_ok=True)
+
+        # Migrate thermal group from Other to Other 1
+        thermal_cluster_dir = study_dir / "input" / "thermal" / "clusters"
+        for area in thermal_cluster_dir.iterdir():
+            ini_path = thermal_cluster_dir / area / "list.ini"
+            sections = IniReader().read(ini_path)
+            for section in sections.values():
+                if section["group"].lower() == "Other".lower():
+                    section["group"] = "other 1"
+            IniWriter().write(sections, ini_path)
diff --git a/tests/upgrade_app/test_upgrade_0801.py b/tests/upgrade_app/test_upgrade_0801.py
index 650a8e4..3a8a1ab 100644
--- a/tests/upgrade_app/test_upgrade_0801.py
+++ b/tests/upgrade_app/test_upgrade_0801.py
@@ -19,7 +19,9 @@ def test_nominal_case(study_assets: StudyAssets):
     expected = IniReader().read(expected_path)
     assert actual == expected
 
-    # compare folders (because the upgrade should create empty "renewables" folder)
+    # compare input folders:
+    # 1- The upgrade should create empty "renewables" folder
+    # 2- The upgrade should rename old thermal groups
     assert are_same_dir(
         study_assets.study_dir.joinpath("input"),
         study_assets.expected_dir.joinpath("input"),
diff --git a/tests/upgrade_app/upgrade_0801/nominal_case/empty_study_0800.expected.zip b/tests/upgrade_app/upgrade_0801/nominal_case/empty_study_0800.expected.zip
deleted file mode 100644
index 4b5f52b..0000000
Binary files a/tests/upgrade_app/upgrade_0801/nominal_case/empty_study_0800.expected.zip and /dev/null differ
diff --git a/tests/upgrade_app/upgrade_0801/nominal_case/empty_study_0800.zip b/tests/upgrade_app/upgrade_0801/nominal_case/empty_study_0800.zip
deleted file mode 100644
index 507d8a9..0000000
Binary files a/tests/upgrade_app/upgrade_0801/nominal_case/empty_study_0800.zip and /dev/null differ
diff --git a/tests/upgrade_app/upgrade_0801/nominal_case/little_study_0800.expected.zip b/tests/upgrade_app/upgrade_0801/nominal_case/little_study_0800.expected.zip
new file mode 100644
index 0000000..c70a79f
Binary files /dev/null and b/tests/upgrade_app/upgrade_0801/nominal_case/little_study_0800.expected.zip differ
diff --git a/tests/upgrade_app/upgrade_0801/nominal_case/little_study_0800.zip b/tests/upgrade_app/upgrade_0801/nominal_case/little_study_0800.zip
new file mode 100644
index 0000000..437220e
Binary files /dev/null and b/tests/upgrade_app/upgrade_0801/nominal_case/little_study_0800.zip differ