diff --git a/rust/theoros/src/services/indexer/mod.rs b/rust/theoros/src/services/indexer/mod.rs
index 9e986c5..e81d15a 100644
--- a/rust/theoros/src/services/indexer/mod.rs
+++ b/rust/theoros/src/services/indexer/mod.rs
@@ -1,3 +1,5 @@
+use std::cmp::max;
+
 use anyhow::{anyhow, bail, Context, Result};
 use apibara_core::{
     node::v1alpha2::DataFinality,
@@ -61,7 +63,7 @@ impl IndexerService {
         current_block: u64,
     ) -> Result<Self> {
         let stream_config = Configuration::<Filter>::default()
-            .with_starting_block(current_block - START_INDEXER_DELTA)
+            .with_starting_block(max(1, current_block.saturating_sub(START_INDEXER_DELTA)))
             .with_filter(|mut filter| {
                 filter
                     .with_header(HeaderFilter::weak())