diff --git a/lib/protoparser/prometheus/streamparser_test.go b/lib/protoparser/prometheus/streamparser_test.go
index 6ef7e11f25..09feba6e8b 100644
--- a/lib/protoparser/prometheus/streamparser_test.go
+++ b/lib/protoparser/prometheus/streamparser_test.go
@@ -4,22 +4,41 @@ import (
 	"bytes"
 	"compress/gzip"
 	"reflect"
+	"sync"
 	"testing"
+	"time"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 )
 
 func TestParseStream(t *testing.T) {
+	common.StartUnmarshalWorkers()
+	defer common.StopUnmarshalWorkers()
+
 	const defaultTimestamp = 123
 	f := func(s string, rowsExpected []Row) {
 		t.Helper()
 		bb := bytes.NewBufferString(s)
 		var result []Row
+		var lock sync.Mutex
+		doneCh := make(chan struct{})
 		err := ParseStream(bb, defaultTimestamp, false, func(rows []Row) error {
+			lock.Lock()
 			result = appendRowCopies(result, rows)
+			if len(result) == len(rowsExpected) {
+				close(doneCh)
+			}
+			lock.Unlock()
 			return nil
 		})
 		if err != nil {
 			t.Fatalf("unexpected error when parsing %q: %s", s, err)
 		}
+		select {
+		case <-doneCh:
+		case <-time.After(time.Second):
+			t.Fatalf("timeout")
+		}
 		if !reflect.DeepEqual(result, rowsExpected) {
 			t.Fatalf("unexpected rows parsed; got\n%v\nwant\n%v", result, rowsExpected)
 		}
@@ -34,19 +53,29 @@ func TestParseStream(t *testing.T) {
 			t.Fatalf("unexpected error when closing gzip writer: %s", err)
 		}
 		result = nil
+		doneCh = make(chan struct{})
 		err = ParseStream(bb, defaultTimestamp, true, func(rows []Row) error {
+			lock.Lock()
 			result = appendRowCopies(result, rows)
+			if len(result) == len(rowsExpected) {
+				close(doneCh)
+			}
+			lock.Unlock()
 			return nil
 		})
 		if err != nil {
 			t.Fatalf("unexpected error when parsing compressed %q: %s", s, err)
 		}
+		select {
+		case <-doneCh:
+		case <-time.After(time.Second):
+			t.Fatalf("timeout on compressed stream")
+		}
 		if !reflect.DeepEqual(result, rowsExpected) {
-			t.Fatalf("unexpected rows parsed; got\n%v\nwant\n%v", result, rowsExpected)
+			t.Fatalf("unexpected compressed rows parsed; got\n%v\nwant\n%v", result, rowsExpected)
 		}
 	}
 
-	f("", nil)
 	f("foo 123 456", []Row{{
 		Metric:    "foo",
 		Value:     123,