diff --git a/tests/cli_test.py b/tests/cli_test.py
index a6b0bd7..f1678c6 100644
--- a/tests/cli_test.py
+++ b/tests/cli_test.py
@@ -2,18 +2,19 @@ from typer.testing import CliRunner
 from corrlib.cli import app
 import os
 import sqlite3 as sql
+from pathlib import Path
 
 
 runner = CliRunner()
 
 
-def test_version():
+def test_version() -> None:
     result = runner.invoke(app, ["--version"])
     assert result.exit_code == 0
     assert "corrlib" in result.output
 
 
-def test_init_folders(tmp_path):
+def test_init_folders(tmp_path: Path) -> None:
     dataset_path = tmp_path / "test_dataset"
     result = runner.invoke(app, ["init", "--dataset", str(dataset_path)])
     assert result.exit_code == 0
@@ -21,7 +22,7 @@ def test_init_folders(tmp_path):
     assert os.path.exists(str(dataset_path / "backlogger.db"))
 
 
-def test_init_db(tmp_path):
+def test_init_db(tmp_path: Path) -> None:
     dataset_path = tmp_path / "test_dataset"
     result = runner.invoke(app, ["init", "--dataset", str(dataset_path)])
     assert result.exit_code == 0
@@ -37,7 +38,7 @@ def test_init_db(tmp_path):
     table_names = [table[0] for table in tables]
     for expected_table in expected_tables:
         assert expected_table in table_names
-    
+
     cursor.execute("SELECT * FROM projects;")
     projects = cursor.fetchall()
     assert len(projects) == 0
@@ -60,7 +61,7 @@ def test_init_db(tmp_path):
     project_column_names = [col[1] for col in project_columns]
     for expected_col in expected_project_columns:
         assert expected_col in project_column_names
-    
+
     cursor.execute("PRAGMA table_info('backlogs');")
     backlog_columns = cursor.fetchall()
     expected_backlog_columns = [
@@ -81,7 +82,7 @@ def test_init_db(tmp_path):
         assert expected_col in backlog_column_names
 
 
-def test_list(tmp_path):
+def test_list(tmp_path: Path) -> None:
     dataset_path = tmp_path / "test_dataset"
     result = runner.invoke(app, ["init", "--dataset", str(dataset_path)])
     assert result.exit_code == 0
diff --git a/tests/import_project_test.py b/tests/import_project_test.py
index 2dea06f..685d2cf 100644
--- a/tests/import_project_test.py
+++ b/tests/import_project_test.py
@@ -1,7 +1,7 @@
 import corrlib.toml as t
 
 
-def test_toml_check_measurement_data():
+def test_toml_check_measurement_data() -> None:
     measurements = {
                     "a":
                         {
diff --git a/tests/sfcf_in_test.py b/tests/sfcf_in_test.py
index 72921e7..5e4ff83 100644
--- a/tests/sfcf_in_test.py
+++ b/tests/sfcf_in_test.py
@@ -1,7 +1,7 @@
 import corrlib.input.sfcf as input
 import json
 
-def test_get_specs():
+def test_get_specs() -> None:
     parameters = {
         'crr': [
             'f_P', 'f_A'
diff --git a/tests/test_initialization.py b/tests/test_initialization.py
index 1ea0ece..9284c82 100644
--- a/tests/test_initialization.py
+++ b/tests/test_initialization.py
@@ -1,22 +1,23 @@
 import corrlib.initialization as init
 import os
 import sqlite3 as sql
+from pathlib import Path
 
-def test_init_folders(tmp_path):
+def test_init_folders(tmp_path: Path) -> None:
     dataset_path = tmp_path / "test_dataset"
     init.create(str(dataset_path))
     assert os.path.exists(str(dataset_path))
     assert os.path.exists(str(dataset_path / "backlogger.db"))
 
 
-def test_init_folders_no_tracker(tmp_path):
+def test_init_folders_no_tracker(tmp_path: Path) -> None:
     dataset_path = tmp_path / "test_dataset"
     init.create(str(dataset_path), tracker="None")
     assert os.path.exists(str(dataset_path))
     assert os.path.exists(str(dataset_path / "backlogger.db"))
 
 
-def test_init_config(tmp_path):
+def test_init_config(tmp_path: Path) -> None:
     dataset_path = tmp_path / "test_dataset"
     init.create(str(dataset_path), tracker="None")
     config_path = dataset_path / ".corrlib"
@@ -34,7 +35,7 @@ def test_init_config(tmp_path):
     assert config.get("paths", "import_scripts_path") == "import_scripts"
 
 
-def test_init_db(tmp_path):
+def test_init_db(tmp_path: Path) -> None:
     dataset_path = tmp_path / "test_dataset"
     init.create(str(dataset_path))
     assert os.path.exists(str(dataset_path / "backlogger.db"))
diff --git a/tests/tools_test.py b/tests/tools_test.py
index ee76f1c..88dbffa 100644
--- a/tests/tools_test.py
+++ b/tests/tools_test.py
@@ -3,29 +3,29 @@
 from corrlib import tools as tl
 
 
-def test_m2k():
+def test_m2k() -> None:
     for m in [0.1, 0.5, 1.0]:
         expected_k = 1 / (2 * m + 8)
         assert tl.m2k(m) == expected_k
 
 
-def test_k2m():
+def test_k2m() -> None:
     for m in [0.1, 0.5, 1.0]:
         assert tl.k2m(m) == (1/(2*m))-4
 
 
-def test_k2m_m2k():
+def test_k2m_m2k() -> None:
     for m in [0.1, 0.5, 1.0]:
         k = tl.m2k(m)
         m_converted = tl.k2m(k)
         assert abs(m - m_converted) < 1e-9
 
 
-def test_str2list():
+def test_str2list() -> None:
     assert tl.str2list("a,b,c") == ["a", "b", "c"]
     assert tl.str2list("1,2,3") == ["1", "2", "3"]
 
 
-def test_list2str():
+def test_list2str() -> None:
     assert tl.list2str(["a", "b", "c"]) == "a,b,c"
     assert tl.list2str(["1", "2", "3"]) == "1,2,3"