diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..5cc3df0
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1,13 @@
+"""
+Adding the __init__.py to the tests/ directory (and its subdirectories) makes them all part of the
+same package structure.
+
+- Allows test modules/files to import from each other (including from modules in different
+  directories, such as files in tests/cli/ importing from tests/testdb.py).
+- Does not require test modules to have unique names.
+
+This necessitates using the "prepend" (or possibly "append"?) import mode (which is the default).
+This setup comes with its own set of caveats. See
+https://docs.pytest.org/en/7.1.x/explanation/pythonpath.html for a discussion of how test modules
+are imported.
+"""
diff --git a/tests/benchmarks/__init__.py b/tests/benchmarks/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/cli/__init__.py b/tests/cli/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/cli/test_cli_common.py b/tests/cli/test_common.py
similarity index 100%
rename from tests/cli/test_cli_common.py
rename to tests/cli/test_common.py
diff --git a/tests/cli/test_cli_dist.py b/tests/cli/test_dist.py
similarity index 100%
rename from tests/cli/test_cli_dist.py
rename to tests/cli/test_dist.py
diff --git a/tests/cli/test_cli_query.py b/tests/cli/test_query.py
similarity index 100%
rename from tests/cli/test_cli_query.py
rename to tests/cli/test_query.py
diff --git a/tests/cli/test_cli_signatures.py b/tests/cli/test_signatures.py
similarity index 100%
rename from tests/cli/test_cli_signatures.py
rename to tests/cli/test_signatures.py
diff --git a/tests/cli/test_cli_tree.py b/tests/cli/test_tree.py
similarity index 100%
rename from tests/cli/test_cli_tree.py
rename to tests/cli/test_tree.py
diff --git a/tests/conftest.py b/tests/conftest.py
index e3431b6..4467af3 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -3,7 +3,8 @@
 import numpy as np
 import pytest
 from sqlalchemy import create_engine
-from testdb import TestDB
+
+from .testdb import TestDB
 
 
 @pytest.fixture(scope='session')
diff --git a/tests/data/__init__.py b/tests/data/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/db/__init__.py b/tests/db/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/db/test_db_migrate.py b/tests/db/test_migrate.py
similarity index 100%
rename from tests/db/test_db_migrate.py
rename to tests/db/test_migrate.py
diff --git a/tests/db/test_db_models.py b/tests/db/test_models.py
similarity index 100%
rename from tests/db/test_db_models.py
rename to tests/db/test_models.py
diff --git a/tests/db/test_db_refdb.py b/tests/db/test_refdb.py
similarity index 100%
rename from tests/db/test_db_refdb.py
rename to tests/db/test_refdb.py
diff --git a/tests/db/test_db_sqla.py b/tests/db/test_sqla.py
similarity index 100%
rename from tests/db/test_db_sqla.py
rename to tests/db/test_sqla.py
diff --git a/tests/sigs/__init__.py b/tests/sigs/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/sigs/test_sigs_base.py b/tests/sigs/test_base.py
similarity index 100%
rename from tests/sigs/test_sigs_base.py
rename to tests/sigs/test_base.py
diff --git a/tests/sigs/test_sigs_calc.py b/tests/sigs/test_calc.py
similarity index 100%
rename from tests/sigs/test_sigs_calc.py
rename to tests/sigs/test_calc.py
diff --git a/tests/sigs/test_sigs_convert.py b/tests/sigs/test_convert.py
similarity index 100%
rename from tests/sigs/test_sigs_convert.py
rename to tests/sigs/test_convert.py
diff --git a/tests/sigs/test_sigs_hdf5.py b/tests/sigs/test_hdf5.py
similarity index 100%
rename from tests/sigs/test_sigs_hdf5.py
rename to tests/sigs/test_hdf5.py
diff --git a/tests/util/__init__.py b/tests/util/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/util/test_util_indexing.py b/tests/util/test_indexing.py
similarity index 100%
rename from tests/util/test_util_indexing.py
rename to tests/util/test_indexing.py
diff --git a/tests/util/test_util_io.py b/tests/util/test_io.py
similarity index 100%
rename from tests/util/test_util_io.py
rename to tests/util/test_io.py
diff --git a/tests/util/test_util_json.py b/tests/util/test_json.py
similarity index 100%
rename from tests/util/test_util_json.py
rename to tests/util/test_json.py
diff --git a/tests/util/test_util_misc.py b/tests/util/test_misc.py
similarity index 100%
rename from tests/util/test_util_misc.py
rename to tests/util/test_misc.py
diff --git a/tests/util/test_util_progress.py b/tests/util/test_progress.py
similarity index 100%
rename from tests/util/test_util_progress.py
rename to tests/util/test_progress.py
diff --git a/tests/util/test_util_typing.py b/tests/util/test_typing.py
similarity index 100%
rename from tests/util/test_util_typing.py
rename to tests/util/test_typing.py