diff --git a/cohortextractor/tpp_backend.py b/cohortextractor/tpp_backend.py
index b896d747..62c61239 100644
--- a/cohortextractor/tpp_backend.py
+++ b/cohortextractor/tpp_backend.py
@@ -41,7 +41,8 @@
 class TPPBackend:
     _db_connection = None
     _current_column_name = None
-    include_t1oo = False
+    # TODO: Temporary default to support safe deployment
+    include_t1oo = True
 
     def __init__(
         self,
diff --git a/tests/test_tpp_backend.py b/tests/test_tpp_backend.py
index dc8baa3f..b3d9fe65 100644
--- a/tests/test_tpp_backend.py
+++ b/tests/test_tpp_backend.py
@@ -152,12 +152,12 @@ def setup_function(function):
         (
             "mssql://user:pass@localhost:4321/db",
             "mssql://user:pass@localhost:4321/db",
-            False,
+            True,
         ),
         (
             "mssql://user:pass@localhost:4321/db?param1=one&param2&param1=three",
             "mssql://user:pass@localhost:4321/db?param1=one&param1=three&param2=",
-            False,
+            True,
         ),
         (
             "mssql://user:pass@localhost:4321/db?opensafely_include_t1oo&param2=two",