diff --git a/packages/sdk/src/actions/waitForFillTx.ts b/packages/sdk/src/actions/waitForFillTx.ts
index 200b24c..82e37bc 100644
--- a/packages/sdk/src/actions/waitForFillTx.ts
+++ b/packages/sdk/src/actions/waitForFillTx.ts
@@ -161,6 +161,10 @@ export function parseFillLogs(
     depositId: bigint | number;
   }>,
 ) {
+  if (logs.length === 0) {
+    return undefined;
+  }
+
   const blockData = {
     depositTxHash: logs[0]!.blockHash!,
     depositTxBlock: logs[0]!.blockNumber!,
diff --git a/packages/sdk/test/unit/actions/parseFillLogs.test.ts b/packages/sdk/test/unit/actions/parseFillLogs.test.ts
new file mode 100644
index 0000000..b1edca7
--- /dev/null
+++ b/packages/sdk/test/unit/actions/parseFillLogs.test.ts
@@ -0,0 +1,26 @@
+import { describe, expect, test } from "vitest";
+import { parseFillLogs } from "../../../src/actions/waitForFillTx.js";
+
+describe("parseFillLogs", () => {
+  test("returns undefined for an empty logs array", () => {
+    expect(parseFillLogs([])).toBeUndefined();
+  });
+
+  test("returns undefined when logs contain no fill events", () => {
+    const unrelatedLog = {
+      address: "0x0000000000000000000000000000000000000001",
+      blockHash:
+        "0x1111111111111111111111111111111111111111111111111111111111111111",
+      blockNumber: 1n,
+      data: "0x",
+      logIndex: 0,
+      transactionHash:
+        "0x2222222222222222222222222222222222222222222222222222222222222222",
+      transactionIndex: 0,
+      removed: false,
+      topics: [],
+    } as const;
+
+    expect(parseFillLogs([unrelatedLog])).toBeUndefined();
+  });
+});