diff --git a/pkg/service/eth/block_id.go b/pkg/service/eth/block_id.go
index ebf05a5a..fdfbc0a2 100644
--- a/pkg/service/eth/block_id.go
+++ b/pkg/service/eth/block_id.go
@@ -83,7 +83,7 @@ func newBlockIdentifier(id BlockIDType, value string) BlockIdentifier {
 }
 
 func NewSlotFromString(id string) (phase0.Slot, error) {
-	slot, err := strconv.ParseInt(id, 10, 64)
+	slot, err := strconv.ParseUint(id, 10, 64)
 	if err != nil {
 		return 0, err
 	}
diff --git a/pkg/service/eth/eth.go b/pkg/service/eth/eth.go
index 881d652f..44faf579 100644
--- a/pkg/service/eth/eth.go
+++ b/pkg/service/eth/eth.go
@@ -565,7 +565,7 @@ func (h *Handler) BlobSidecars(ctx context.Context, blockID BlockIdentifier, ind
 
 		// Find the sidecar with the given index
 		for i, sidecar := range sidecars {
-			if index == int(sidecar.Index) {
+			if deneb.BlobIndex(index) == sidecar.Index {
 				filtered = append(filtered, sidecars[i])
 
 				break