diff --git a/app/vmalert/config/config.go b/app/vmalert/config/config.go
index f027dad59..cd40af7af 100644
--- a/app/vmalert/config/config.go
+++ b/app/vmalert/config/config.go
@@ -41,7 +41,7 @@ func (g *Group) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	}
 	b, err := yaml.Marshal(g)
 	if err != nil {
-		return fmt.Errorf("failed to marshal group configuration for checksum: %s", err)
+		return fmt.Errorf("failed to marshal group configuration for checksum: %w", err)
 	}
 	h := md5.New()
 	h.Write(b)
diff --git a/app/vmselect/promql/rollup.go b/app/vmselect/promql/rollup.go
index d6351e523..6d612fee9 100644
--- a/app/vmselect/promql/rollup.go
+++ b/app/vmselect/promql/rollup.go
@@ -474,6 +474,11 @@ func (rc *rollupConfig) doInternal(dstValues []float64, tsm *timeseriesMap, valu
 	window := rc.Window
 	if window <= 0 {
 		window = rc.Step
+		if rc.LookbackDelta > 0 && window > rc.LookbackDelta {
+			// Implicitly set window exceeds -search.maxStalenessInterval, so limit it to -search.maxStalenessInterval
+			// according to https://github.com/VictoriaMetrics/VictoriaMetrics/issues/784
+			window = rc.LookbackDelta
+		}
 	}
 	if rc.MayAdjustWindow && window < maxPrevInterval {
 		window = maxPrevInterval
diff --git a/app/vmselect/promql/rollup_test.go b/app/vmselect/promql/rollup_test.go
index c75626f45..d698d8c8e 100644
--- a/app/vmselect/promql/rollup_test.go
+++ b/app/vmselect/promql/rollup_test.go
@@ -645,7 +645,7 @@ func TestRollupFuncsLookbackDelta(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{99, nan, 44, nan, 32, 34, nan}
+		valuesExpected := []float64{12, nan, nan, nan, 34, 34, nan}
 		timestampsExpected := []int64{80, 90, 100, 110, 120, 130, 140}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
diff --git a/lib/promscrape/discovery/ec2/api_test.go b/lib/promscrape/discovery/ec2/api_test.go
index a37c33ce5..b067880b1 100644
--- a/lib/promscrape/discovery/ec2/api_test.go
+++ b/lib/promscrape/discovery/ec2/api_test.go
@@ -114,7 +114,7 @@ func TestParseARNCredentialsSuccess(t *testing.T) {
 func mustParseRFC3339(s string) time.Time {
 	expTime, err := time.Parse(time.RFC3339, s)
 	if err != nil {
-		panic(fmt.Errorf("unexpected error when parsing time from %q: %s", s, err))
+		panic(fmt.Errorf("unexpected error when parsing time from %q: %w", s, err))
 	}
 	return expTime
 }