diff --git a/rtc_base/rate_statistics.cc b/rtc_base/rate_statistics.cc
index 85621fa555..5c83796471 100644
--- a/rtc_base/rate_statistics.cc
+++ b/rtc_base/rate_statistics.cc
@@ -58,7 +58,7 @@ void RateStatistics::Update(int64_t count, int64_t now_ms) {
   RTC_DCHECK_GE(count, 0);
 
   EraseOld(now_ms);
-  if (first_timestamp_ == -1) {
+  if (first_timestamp_ == -1 || num_samples_ == 0) {
     first_timestamp_ = now_ms;
   }
 
diff --git a/rtc_base/rate_statistics_unittest.cc b/rtc_base/rate_statistics_unittest.cc
index 735677082b..8f1a8384cf 100644
--- a/rtc_base/rate_statistics_unittest.cc
+++ b/rtc_base/rate_statistics_unittest.cc
@@ -148,14 +148,15 @@ TEST_F(RateStatisticsTest, ResetAfterSilence) {
 
   now_ms += kWindowMs + 1;
   EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms)));
+  // Silence over window size should trigger auto reset for coming sample.
   stats_.Update(1000, now_ms);
   ++now_ms;
   stats_.Update(1000, now_ms);
   // We expect two samples of 1000 bytes, and that the bitrate is measured over
-  // 500 ms, i.e. 2 * 8 * 1000 / 0.500 = 32000.
-  EXPECT_EQ(32000u, *stats_.Rate(now_ms));
+  // active window instead of full window, which is now_ms - first_timestamp + 1
+  EXPECT_EQ(kExpectedBitrate, *stats_.Rate(now_ms));
 
-  // Reset, add the same samples again.
+  // Manual reset, add the same samples again.
   stats_.Reset();
   EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms)));
   stats_.Update(1000, now_ms);
@@ -272,9 +273,16 @@ TEST_F(RateStatisticsTest, HandlesQuietPeriods) {
   EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms)));
 
   // Move window a long way out.
+  // This will cause an automatic reset of the window
+  // First data point won't give a valid result
   now_ms += 2 * kWindowMs;
   stats_.Update(0, now_ms);
   bitrate = stats_.Rate(now_ms);
+  EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms)));
+  // Second data point gives valid result
+  ++now_ms;
+  stats_.Update(0, now_ms);
+  bitrate = stats_.Rate(now_ms);
   EXPECT_TRUE(static_cast<bool>(bitrate));
   EXPECT_EQ(0u, *bitrate);
 }