diff --git a/src/main/resources/db/migration/V001.001__datasets_array.sql b/src/main/resources/db/migration/V001.001__datasets_array.sql
new file mode 100644
index 00000000..9210e449
--- /dev/null
+++ b/src/main/resources/db/migration/V001.001__datasets_array.sql
@@ -0,0 +1,39 @@
+-- See the NOTICE file distributed with this work for additional information
+-- regarding copyright ownership.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+-- Updates trial.additional_info to have a datasets array instead of just observationDatasetId.
+-- Leaves observationDatasetId in place out of an abundance of caution.
+-- Only updates rows that don't already have datasets key (just in case the code was updated prematurely).
+DO
+$$
+BEGIN
+    UPDATE
+        trial
+    SET
+        additional_info = additional_info
+            || JSONB_BUILD_OBJECT(
+                'datasets',
+                JSONB_BUILD_ARRAY(
+                    JSONB_BUILD_OBJECT(
+                        'id', additional_info->'observationDatasetId',
+                        'name', additional_info->'defaultObservationLevel',
+                        'level', '0'
+                    )
+                )
+            )
+    WHERE
+        additional_info->'datasets' IS NULL;
+END
+$$;