diff --git a/datasette/app.py b/datasette/app.py
index 0227f627..b1630122 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -310,6 +310,9 @@ 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())