diff --git a/src/ert/storage/local_storage.py b/src/ert/storage/local_storage.py
index c8f9de3001b..484c2d1ef2b 100644
--- a/src/ert/storage/local_storage.py
+++ b/src/ert/storage/local_storage.py
@@ -556,6 +556,7 @@ def _write_transaction(self, filename: str | os.PathLike[str], data: bytes) -> N
         self._swap_path.mkdir(parents=True, exist_ok=True)
         with NamedTemporaryFile(dir=self._swap_path, delete=False) as f:
             f.write(data)
+            os.chmod(f.name, 0o666)
             os.rename(f.name, filename)
 
     def _to_netcdf_transaction(
@@ -570,6 +571,7 @@ def _to_netcdf_transaction(
         self._swap_path.mkdir(parents=True, exist_ok=True)
         with NamedTemporaryFile(dir=self._swap_path, delete=False) as f:
             dataset.to_netcdf(f, engine="scipy")
+            os.chmod(f.name, 0o666)
             os.rename(f.name, filename)
 
     def _to_parquet_transaction(
@@ -584,6 +586,7 @@ def _to_parquet_transaction(
         self._swap_path.mkdir(parents=True, exist_ok=True)
         with NamedTemporaryFile(dir=self._swap_path, delete=False) as f:
             dataframe.write_parquet(f.name)
+            os.chmod(f.name, 0o666)
             os.rename(f.name, filename)
 
 
diff --git a/src/ert/storage/migration/to9.py b/src/ert/storage/migration/to9.py
index 5d8e07c2399..01febf99488 100644
--- a/src/ert/storage/migration/to9.py
+++ b/src/ert/storage/migration/to9.py
@@ -19,6 +19,7 @@ def _write_transaction(filename: str | os.PathLike[str], data: bytes) -> None:
     Path("./swp").mkdir(parents=True, exist_ok=True)
     with NamedTemporaryFile(dir="./swp", delete=False) as f:
         f.write(data)
+        os.chmod(f.name, 0o666)
         os.rename(f.name, filename)
 
 
diff --git a/tests/ert/unit_tests/storage/test_local_storage.py b/tests/ert/unit_tests/storage/test_local_storage.py
index 2edf11cce8b..814103dac87 100644
--- a/tests/ert/unit_tests/storage/test_local_storage.py
+++ b/tests/ert/unit_tests/storage/test_local_storage.py
@@ -1,6 +1,7 @@
 import json
 import os
 import shutil
+import stat
 import tempfile
 from dataclasses import dataclass, field
 from datetime import datetime, timedelta
@@ -585,6 +586,7 @@ def test_write_transaction(data):
         filepath = Path("./file.txt")
         storage._write_transaction(filepath, data)
 
+        assert stat.S_IMODE(filepath.stat().st_mode) == 0o666
         assert filepath.read_bytes() == data