diff --git a/.changeset/fix-empty-v3-fill-logs.md b/.changeset/fix-empty-v3-fill-logs.md
new file mode 100644
index 0000000..e22c1c3
--- /dev/null
+++ b/.changeset/fix-empty-v3-fill-logs.md
@@ -0,0 +1,5 @@
+---
+"@across-protocol/app-sdk": patch
+---
+
+Fix `getFillLogs` returning an empty `v3Logs` array instead of falling back to `v3_5Logs`. The previous `v3Logs ?? v3_5Logs` check never fell through because `getContractEvents` always returns an array, so fills emitted via the v3.5 `FilledRelay` event were not found by `getFillByDepositTx`.
diff --git a/packages/sdk/src/actions/getFillByDepositTx.ts b/packages/sdk/src/actions/getFillByDepositTx.ts
index 875f7c9..479c69d 100644
--- a/packages/sdk/src/actions/getFillByDepositTx.ts
+++ b/packages/sdk/src/actions/getFillByDepositTx.ts
@@ -413,5 +413,5 @@ export async function getFillLogs(params: GetFillByDepositTxParams) {
     }),
   ]);
 
-  return v3Logs ?? v3_5Logs;
+  return v3Logs.length ? v3Logs : v3_5Logs;
 }