diff --git a/docs/VictoriaLogs/CHANGELOG.md b/docs/VictoriaLogs/CHANGELOG.md
index d6474b93f..8e2037265 100644
--- a/docs/VictoriaLogs/CHANGELOG.md
+++ b/docs/VictoriaLogs/CHANGELOG.md
@@ -15,6 +15,8 @@ according to [these docs](https://docs.victoriametrics.com/victorialogs/quicksta
 
 ## tip
 
+* BUGFIX: fix `runtime error: index out of range [0] with length 0` panic during low-rate data ingestion. The panic has been introduced in [v0.38.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.38.0-victorialogs). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7391).
+
 ## [v0.38.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.38.0-victorialogs)
 
 Released at 2024-10-29
diff --git a/lib/logstorage/block_stream_writer.go b/lib/logstorage/block_stream_writer.go
index 3d3a54382..fcffb3eab 100644
--- a/lib/logstorage/block_stream_writer.go
+++ b/lib/logstorage/block_stream_writer.go
@@ -312,7 +312,10 @@ func (bsw *blockStreamWriter) MustInitForFilePart(path string, nocache bool, blo
 
 func adjustBloomValuesShardsCount(n uint64) uint64 {
 	if n == 0 {
-		return n
+		// At least a single shard is needed for writing potential non-const fields,
+		// which can appear after merging of const fields.
+		// This fixes https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7391
+		return 1
 	}
 
 	n = 1 << bits.Len64(n-1)