diff --git a/examples/idxd/perf/perf.c b/examples/idxd/perf/perf.c
index 5786593d4..c1c99cf72 100644
--- a/examples/idxd/perf/perf.c
+++ b/examples/idxd/perf/perf.c
@@ -523,7 +523,7 @@ _submit_single(struct idxd_chan_entry *t, struct idxd_task *task)
 		/* For fill use the first byte of the task->dst buffer */
 		diov.iov_base = task->dst;
 		diov.iov_len = g_xfer_size_bytes;
-		rc = spdk_idxd_submit_fill(t->ch, &diov, 1, *(uint8_t *)task->src,
+		rc = spdk_idxd_submit_fill(t->ch, &diov, 1, *(uint64_t *)task->src,
 					   flags, idxd_done, task);
 		break;
 	case IDXD_CRC32C: