diff --git a/datasette/app.py b/datasette/app.py
index b1630122..0227f627 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -310,9 +310,6 @@ class Datasette:
                 Database(self, file, is_mutable=file not in self.immutables)
             )
 
-        if internal is None and "DATASETTE_INTERNAL_DB_PATH" in os.environ:
-            internal = os.environ.get("DATASETTE_INTERNAL_DB_PATH")
-
         self.internal_db_created = False
         if internal is None:
             self._internal_database = Database(self, memory_name=secrets.token_hex())
diff --git a/datasette/cli.py b/datasette/cli.py
index 1a5a8af3..f3ea7d04 100644
--- a/datasette/cli.py
+++ b/datasette/cli.py
@@ -477,6 +477,7 @@ def uninstall(packages, yes):
     "--internal",
     type=click.Path(),
     help="Path to a persistent Datasette internal SQLite database",
+    envvar="DATASETTE_INTERNAL"
 )
 def serve(
     files,