diff --git a/packages/filecoin-api/src/dealer/events.js b/packages/filecoin-api/src/dealer/events.js
index 65f69cb63..c035a9123 100644
--- a/packages/filecoin-api/src/dealer/events.js
+++ b/packages/filecoin-api/src/dealer/events.js
@@ -17,7 +17,7 @@ export const handleAggregateInsert = async (context, record) => {
   const updateRes = await context.offerStore.update(record.pieces.toString(), {
     key: `${new Date(
       record.insertedAt
-    ).toISOString()} ${record.aggregate.toString()}.json`,
+    ).toISOString()}_${record.aggregate.toString()}.json`,
   })
   if (updateRes.error) {
     return { error: new StoreOperationFailed(updateRes.error.message) }
diff --git a/packages/filecoin-api/test/events/dealer.js b/packages/filecoin-api/test/events/dealer.js
index d8f0af430..f176ef807 100644
--- a/packages/filecoin-api/test/events/dealer.js
+++ b/packages/filecoin-api/test/events/dealer.js
@@ -72,7 +72,7 @@ export const test = {
     const offerStoreGetAfterRename1 = await context.offerStore.get(
       `${new Date(
         aggregateRecord.insertedAt
-      ).toISOString()} ${aggregateRecord.aggregate.toString()}.json`
+      ).toISOString()}_${aggregateRecord.aggregate.toString()}.json`
     )
     assert.ok(offerStoreGetAfterRename1.ok)
   },