diff --git a/driver/bpf/fillers.h b/driver/bpf/fillers.h
index 7a483bef76..b0a536ed50 100644
--- a/driver/bpf/fillers.h
+++ b/driver/bpf/fillers.h
@@ -456,11 +456,11 @@ static __always_inline int bpf_parse_readv_writev_bufs(struct filler_data *data,
 
 #ifdef BPF_FORBIDS_ZERO_ACCESS
 				if (to_read)
-					if (bpf_probe_read(&data->buf[off & SCRATCH_SIZE_HALF],
+					if (bpf_probe_read(&data->buf[off & SCRATCH_SIZE_HALF - 1],
 							   ((to_read - 1) & SCRATCH_SIZE_HALF) + 1,
 							   iov[j].iov_base))
 #else
-				if (bpf_probe_read(&data->buf[off & SCRATCH_SIZE_HALF],
+				if (bpf_probe_read(&data->buf[off & SCRATCH_SIZE_HALF - 1],
 						   to_read & SCRATCH_SIZE_HALF,
 						   iov[j].iov_base))
 #endif