diff --git a/tests/test_geomopt_cli.py b/tests/test_geomopt_cli.py
index 6c8a2c1a..c3450d3a 100644
--- a/tests/test_geomopt_cli.py
+++ b/tests/test_geomopt_cli.py
@@ -8,7 +8,7 @@
 import yaml
 
 from janus_core.cli import app
-from tests.utils import check_log_contents, read_atoms
+from tests.utils import assert_log_contains, read_atoms
 
 DATA_PATH = Path(__file__).parent / "data"
 
@@ -75,7 +75,7 @@ def test_log(tmp_path):
     )
     assert result.exit_code == 0
 
-    check_log_contents(
+    assert_log_contains(
         log_path, includes="Starting geometry optimization", excludes="Using filter"
     )
 
@@ -131,7 +131,9 @@ def test_fully_opt(tmp_path):
     )
     assert result.exit_code == 0
 
-    check_log_contents(log_path, includes=["Using filter", "hydrostatic_strain: False"])
+    assert_log_contains(
+        log_path, includes=["Using filter", "hydrostatic_strain: False"]
+    )
 
     atoms = read(results_path)
     expected = [5.68834069, 5.68893345, 5.68932555, 89.75938298, 90.0, 90.0]
@@ -162,7 +164,7 @@ def test_fully_opt_and_vectors(tmp_path):
     )
     assert result.exit_code == 0
 
-    check_log_contents(log_path, includes=["Using filter", "hydrostatic_strain: True"])
+    assert_log_contains(log_path, includes=["Using filter", "hydrostatic_strain: True"])
 
     atoms = read(results_path)
     expected = [5.69139709, 5.69139709, 5.69139709, 89.0, 90.0, 90.0]
@@ -192,7 +194,7 @@ def test_vectors_not_fully_opt(tmp_path):
     )
     assert result.exit_code == 0
 
-    check_log_contents(log_path, includes=["Using filter", "hydrostatic_strain: True"])
+    assert_log_contains(log_path, includes=["Using filter", "hydrostatic_strain: True"])
 
 
 def test_duplicate_traj(tmp_path):
diff --git a/tests/test_log.py b/tests/test_log.py
index 00c12a53..82aa4bc5 100644
--- a/tests/test_log.py
+++ b/tests/test_log.py
@@ -3,7 +3,7 @@
 import yaml
 
 from janus_core.log import config_logger
-from tests.utils import check_log_contents
+from tests.utils import assert_log_contains
 
 
 def test_multiline_log(tmp_path):
@@ -27,4 +27,4 @@ def test_multiline_log(tmp_path):
     assert log_dicts[0]["level"] == "INFO"
     assert len(log_dicts[0]["message"]) == 3
 
-    check_log_contents(log_path, includes=["Line 1", "Line 4"])
+    assert_log_contains(log_path, includes=["Line 1", "Line 4"])
diff --git a/tests/test_md_cli.py b/tests/test_md_cli.py
index c4c4c096..86b4167a 100644
--- a/tests/test_md_cli.py
+++ b/tests/test_md_cli.py
@@ -9,7 +9,7 @@
 import yaml
 
 from janus_core.cli import app
-from tests.utils import check_log_contents
+from tests.utils import assert_log_contains
 
 DATA_PATH = Path(__file__).parent / "data"
 
@@ -105,7 +105,7 @@ def test_log(tmp_path):
     )
     assert result.exit_code == 0
 
-    check_log_contents(log_path, includes=["Starting molecular dynamics simulation"])
+    assert_log_contains(log_path, includes=["Starting molecular dynamics simulation"])
 
     with open(tmp_path / "nvt-T300-stats.dat", encoding="utf8") as stats_file:
         lines = stats_file.readlines()
diff --git a/tests/test_singlepoint_cli.py b/tests/test_singlepoint_cli.py
index cd9e25cc..00ae64e5 100644
--- a/tests/test_singlepoint_cli.py
+++ b/tests/test_singlepoint_cli.py
@@ -7,7 +7,7 @@
 import yaml
 
 from janus_core.cli import app
-from tests.utils import check_log_contents, read_atoms
+from tests.utils import assert_log_contains, read_atoms
 
 DATA_PATH = Path(__file__).parent / "data"
 
@@ -192,7 +192,7 @@ def test_log(tmp_path):
     )
     assert result.exit_code == 0
 
-    check_log_contents(log_path, includes=["Starting single point calculation"])
+    assert_log_contains(log_path, includes=["Starting single point calculation"])
 
 
 def test_summary(tmp_path):
diff --git a/tests/utils.py b/tests/utils.py
index 42135f29..65749e0c 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,7 +1,7 @@
 """Utility functions for tests."""
 
 from pathlib import Path
-from typing import Optional, Union
+from typing import Union
 
 from ase import Atoms
 from ase.io import read
@@ -35,8 +35,9 @@ def read_atoms(path: Path) -> Union[Atoms, None]:
     return atoms if atoms else None
 
 
-def check_log_contents(
-    log_path: PathLike, *,
+def assert_log_contains(
+    log_path: PathLike,
+    *,
     includes: MaybeSequence[str] = (),
     excludes: MaybeSequence[str] = (),
 ) -> None: