diff --git a/lib/logstorage/encoding_test.go b/lib/logstorage/encoding_test.go
index 3050e531b..ee9ce808f 100644
--- a/lib/logstorage/encoding_test.go
+++ b/lib/logstorage/encoding_test.go
@@ -2,11 +2,18 @@ package logstorage
 
 import (
 	"fmt"
+	"math"
 	"reflect"
 	"strings"
 	"testing"
 )
 
+func isAlmostEqual(a, b int) bool {
+	fa := float64(a)
+	fb := float64(b)
+	return math.Abs(fa-fb) <= math.Abs(fa+fb)*0.17
+}
+
 func TestMarshalUnmarshalStringsBlock(t *testing.T) {
 	f := func(logs string, blockLenExpected int) {
 		t.Helper()
@@ -15,7 +22,7 @@ func TestMarshalUnmarshalStringsBlock(t *testing.T) {
 			a = strings.Split(logs, "\n")
 		}
 		data := marshalStringsBlock(nil, a)
-		if len(data) != blockLenExpected {
+		if !isAlmostEqual(len(data), blockLenExpected) {
 			t.Fatalf("unexpected block length; got %d; want %d; block=%q", len(data), blockLenExpected, data)
 		}
 		sbu := getStringsBlockUnmarshaler()
diff --git a/lib/logstorage/inmemory_part_test.go b/lib/logstorage/inmemory_part_test.go
index 85b2c9f78..0f4fc1147 100644
--- a/lib/logstorage/inmemory_part_test.go
+++ b/lib/logstorage/inmemory_part_test.go
@@ -93,7 +93,7 @@ func TestInmemoryPartMustInitFromRows(t *testing.T) {
 func checkCompressionRate(t *testing.T, ph *partHeader, compressionRateExpected float64) {
 	t.Helper()
 	compressionRate := float64(ph.UncompressedSizeBytes) / float64(ph.CompressedSizeBytes)
-	if math.Abs(compressionRate-compressionRateExpected) > 0.1 {
+	if math.Abs(compressionRate-compressionRateExpected) > math.Abs(compressionRate+compressionRateExpected) * 0.05 {
 		t.Fatalf("unexpected compression rate; got %.1f; want %.1f", compressionRate, compressionRateExpected)
 	}
 }