diff --git a/engine/history_test.go b/engine/history_test.go
index 0d0355986..e7541f5cf 100644
--- a/engine/history_test.go
+++ b/engine/history_test.go
@@ -27,7 +27,7 @@ import (
 
 func TestHistoryRatinPlans(t *testing.T) {
 	scribe := historyScribe.(*history.MockScribe)
-	buf := scribe.BufMap[history.RATING_PROFILES_FN]
+	buf := scribe.GetBuffer(history.RATING_PROFILES_FN)
 	if !strings.Contains(buf.String(), `{"Id":"*out:vdf:0:minu","RatingPlanActivations":[{"ActivationTime":"2012-01-01T00:00:00Z","RatingPlanId":"EVENING","FallbackKeys":null}]}`) {
 		t.Error("Error in destination history content:", buf.String())
 	}
@@ -35,7 +35,7 @@ func TestHistoryRatinPlans(t *testing.T) {
 
 func TestHistoryDestinations(t *testing.T) {
 	scribe := historyScribe.(*history.MockScribe)
-	buf := scribe.BufMap[history.DESTINATIONS_FN]
+	buf := scribe.GetBuffer(history.DESTINATIONS_FN)
 	expected := `[{"Id":"ALL","Prefixes":["49","41","43"]},
 {"Id":"DST_UK_Mobile_BIG5","Prefixes":["447956"]},
 {"Id":"GERMANY","Prefixes":["49"]},
diff --git a/history/mock_scribe.go b/history/mock_scribe.go
index 808298a8e..df110e4a4 100644
--- a/history/mock_scribe.go
+++ b/history/mock_scribe.go
@@ -38,8 +38,10 @@ func NewMockScribe() (*MockScribe, error) {
 }
 
 func (s *MockScribe) Record(rec Record, out *int) error {
+	s.mu.Lock()
 	fn := rec.Filename
 	recordsMap[fn] = recordsMap[fn].SetOrAdd(&rec)
+	s.mu.Unlock()
 	s.save(fn)
 	return nil
 }
@@ -56,3 +58,9 @@ func (s *MockScribe) save(filename string) error {
 	}
 	return nil
 }
+
+func (s *MockScribe) GetBuffer(fn string) *bytes.Buffer {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.BufMap[fn]
+}