diff --git a/storage/local/codable/codable_test.go b/storage/local/codable/codable_test.go
index 501399913..d5c9cdf83 100644
--- a/storage/local/codable/codable_test.go
+++ b/storage/local/codable/codable_test.go
@@ -32,7 +32,7 @@ func newLabelName(ln string) *LabelName {
 
 func TestUint64(t *testing.T) {
 	var b bytes.Buffer
-	const n = 422010471112345
+	const n = uint64(422010471112345)
 	if err := EncodeUint64(&b, n); err != nil {
 		t.Fatal(err)
 	}
diff --git a/storage/local/storage_test.go b/storage/local/storage_test.go
index 6ebbb1a36..9801d6b0e 100644
--- a/storage/local/storage_test.go
+++ b/storage/local/storage_test.go
@@ -803,7 +803,7 @@ func createRandomSamples(metricName string, minLen int) clientmodel.Samples {
 						return clientmodel.SampleValue(rand.Intn(1<<16) - 1<<15 + int(v))
 					},
 					func(v clientmodel.SampleValue) clientmodel.SampleValue {
-						return clientmodel.SampleValue(rand.Intn(1<<32) - 1<<31 + int(v))
+						return clientmodel.SampleValue(rand.Int63n(1<<32) - 1<<31 + int64(v))
 					},
 				},
 			},