diff --git a/Makefile b/Makefile
index db89961..05cea8e 100644
--- a/Makefile
+++ b/Makefile
@@ -129,10 +129,10 @@ upload: build ## Upload the code
 	@twine upload dist/things.py*
 
 db-to-things:
-	@cp tests/main.sqlite* ~/Library/Group\ Containers/JLMPQHK86H.com.culturedcode.ThingsMac/Things\ Database.thingsdatabase/
+	@cp tests/main.sqlite* ~/Library/Group\ Containers/JLMPQHK86H.com.culturedcode.ThingsMac/ThingsData-*/Things\ Database.thingsdatabase/
 
 db-from-things:
-	@cp ~/Library/Group\ Containers/JLMPQHK86H.com.culturedcode.ThingsMac/Things\ Database.thingsdatabase/main.sqlite* tests/
+	@cp ~/Library/Group\ Containers/JLMPQHK86H.com.culturedcode.ThingsMac/ThingsData-*/Things\ Database.thingsdatabase/main.sqlite* tests
 
 info:
 	pipenv --venv
diff --git a/tests/db2022/main.sqlite b/tests/db2022/main.sqlite
new file mode 100644
index 0000000..846d35b
Binary files /dev/null and b/tests/db2022/main.sqlite differ
diff --git a/tests/db2022/main.sqlite-shm b/tests/db2022/main.sqlite-shm
new file mode 100644
index 0000000..33d7b42
Binary files /dev/null and b/tests/db2022/main.sqlite-shm differ
diff --git a/tests/db2022/main.sqlite-wal b/tests/db2022/main.sqlite-wal
new file mode 100644
index 0000000..580b64f
Binary files /dev/null and b/tests/db2022/main.sqlite-wal differ
diff --git a/tests/main.sqlite b/tests/main.sqlite
index 846d35b..587f3ae 100644
Binary files a/tests/main.sqlite and b/tests/main.sqlite differ
diff --git a/tests/main.sqlite-shm b/tests/main.sqlite-shm
index 33d7b42..fe9ac28 100644
Binary files a/tests/main.sqlite-shm and b/tests/main.sqlite-shm differ
diff --git a/tests/main.sqlite-wal b/tests/main.sqlite-wal
index 580b64f..e69de29 100644
Binary files a/tests/main.sqlite-wal and b/tests/main.sqlite-wal differ
diff --git a/tests/main.sqlite.temporary-shm b/tests/main.sqlite.temporary-shm
new file mode 100644
index 0000000..d80de6a
Binary files /dev/null and b/tests/main.sqlite.temporary-shm differ
diff --git a/tests/test_things.py b/tests/test_things.py
index 6065a5f..d62d346 100644
--- a/tests/test_things.py
+++ b/tests/test_things.py
@@ -13,6 +13,7 @@
 
 
 TEST_DATABASE_FILEPATH = "tests/main.sqlite"
+TEST_DATABASE_FILEPATH_2022 = "tests/db2022/main.sqlite"
 
 THINGSDB = things.database.ENVIRONMENT_VARIABLE_WITH_FILEPATH  # type: ignore
 
@@ -243,7 +244,12 @@ def test_areas(self):
 
     def test_database_version(self):
         version = things.Database().get_version()
-        self.assertEqual(18, version)
+        self.assertEqual(24, version)
+
+    def test_database_version_mismatch(self):
+        os.environ[THINGSDB] = TEST_DATABASE_FILEPATH_2022
+        with self.assertRaises(AssertionError):
+            things.deadlines()
 
     def test_last(self):
         last_tasks = things.last("0d")
diff --git a/things/database.py b/things/database.py
index c52a652..8b53770 100755
--- a/things/database.py
+++ b/things/database.py
@@ -148,6 +148,8 @@ class Database:
         Print every SQL query performed. Some may contain '?' and ':'
         characters which correspond to SQLite parameter tokens.
         See https://www.sqlite.org/lang_expr.html#varparam
+
+    :raises AssertionError: If the database version is too old.
     """
 
     debug = False
@@ -164,6 +166,11 @@ def __init__(self, filepath=None, print_sql=False):
         if self.print_sql:
             self.execute_query_count = 0
 
+        # Test for migrated database in Things 3.15.16+
+        # --------------------------------
+        assert self.get_version() > 21, "Database too new! "\
+            "Run 'pip install things.py==0.0.14' to downgrade.";
+
         # Automated migration to new database location in Things 3.12.6/3.13.1
         # --------------------------------
         try: