diff --git a/app/vmselect/promql/eval.go b/app/vmselect/promql/eval.go
index 7f7dc90a0a..fc1b4cefb6 100644
--- a/app/vmselect/promql/eval.go
+++ b/app/vmselect/promql/eval.go
@@ -1100,6 +1100,9 @@ func evalRollupFuncWithMetricExpr(qt *querytracer.Tracer, ec *EvalConfig, funcNa
 	} else {
 		minTimestamp -= ec.Step
 	}
+	if minTimestamp < 0 {
+		minTimestamp = 0
+	}
 	sq := storage.NewSearchQuery(ec.AuthToken.AccountID, ec.AuthToken.ProjectID, minTimestamp, ec.End, tfss, ec.MaxSeries)
 	rss, isPartial, err := netstorage.ProcessSearchQuery(qt, ec.DenyPartialResponse, sq, ec.Deadline)
 	if err != nil {
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index f438479b98..2cdd7c8266 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -50,6 +50,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 * BUGFIX: add validation for invalid [partial RFC3339 timestamp formats](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#timestamp-formats) in query and export APIs.
 * BUGFIX: [vmctl](https://docs.victoriametrics.com/vmctl.html): interrupt explore procedure in influx mode if vmctl found no numeric fields.
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): use RFC3339 time format in query args instead of unix timestamp for all issued queries to Prometheus-like datasources.
+* BUGFIX: vmselect: fix timestamp alignment for Prometheus querying API if time argument is less than 10m from the beginning of Unix epoch.
 
 ## [v1.91.3](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.91.3)