diff --git a/logging/rtc_event_log/rtc_event_log_impl_unittest.cc b/logging/rtc_event_log/rtc_event_log_impl_unittest.cc
index d32af8fe23..aea6c7974e 100644
--- a/logging/rtc_event_log/rtc_event_log_impl_unittest.cc
+++ b/logging/rtc_event_log/rtc_event_log_impl_unittest.cc
@@ -80,7 +80,7 @@ class FakeConfigEvent : public RtcEvent {
 class RtcEventLogImplTest : public ::testing::Test {
  public:
   static constexpr size_t kMaxEventsInHistory = 2;
-  static constexpr size_t kMaxEventsInConfigHistory = 3;
+  static constexpr size_t kMaxEventsInConfigHistory = 5;
   static constexpr TimeDelta kOutputPeriod = TimeDelta::Seconds(2);
   static constexpr Timestamp kStartTime = Timestamp::Seconds(1);
 
@@ -132,6 +132,26 @@ TEST_F(RtcEventLogImplTest, KeepsMostRecentEventsOnStart) {
   Mock::VerifyAndClearExpectations(encoder_ptr_);
 }
 
+TEST_F(RtcEventLogImplTest, KeepsConfigEventsOnStart) {
+  // The config-history is supposed to be unbounded and never overflow.
+  auto c1 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c1_ptr = c1.get();
+  auto c2 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c2_ptr = c2.get();
+  auto c3 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c3_ptr = c3.get();
+  event_log_.Log(std::move(c1));
+  event_log_.Log(std::move(c2));
+  event_log_.Log(std::move(c3));
+  InSequence s;
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c1_ptr)));
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c2_ptr)));
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c3_ptr)));
+  event_log_.StartLogging(std::move(output_), kOutputPeriod.ms());
+  time_controller_.AdvanceTime(TimeDelta::Zero());
+  Mock::VerifyAndClearExpectations(encoder_ptr_);
+}
+
 TEST_F(RtcEventLogImplTest, EncodesEventsOnHistoryFullPostponesLastEncode) {
   auto e1 = std::make_unique<FakeEvent>();
   RtcEvent* e1_ptr = e1.get();
@@ -155,14 +175,41 @@ TEST_F(RtcEventLogImplTest, EncodesEventsOnHistoryFullPostponesLastEncode) {
   Mock::VerifyAndClearExpectations(encoder_ptr_);
 }
 
-TEST_F(RtcEventLogImplTest, RewritesConfigEventsOnlyOnRestart) {
+TEST_F(RtcEventLogImplTest, RewritesAllConfigEventsOnlyOnRestart) {
+  auto c1 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c1_ptr = c1.get();
+  auto c2 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c2_ptr = c2.get();
+  auto c3 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c3_ptr = c3.get();
+  auto c4 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c4_ptr = c4.get();
+  auto c5 = std::make_unique<FakeConfigEvent>();
+  RtcEvent* c5_ptr = c5.get();
+  // Keep the config event before start.
+  event_log_.Log(std::move(c1));
+  // Start logging.
   event_log_.StartLogging(std::make_unique<FakeOutput>(written_data_),
                           kOutputPeriod.ms());
-  event_log_.Log(std::make_unique<FakeConfigEvent>());
+  event_log_.Log(std::move(c2));
+  event_log_.Log(std::move(c3));
+  event_log_.StopLogging();
+  time_controller_.AdvanceTime(TimeDelta::Zero());
+  // Restart logging.
+  event_log_.StartLogging(std::make_unique<FakeOutput>(written_data_),
+                          kOutputPeriod.ms());
+  event_log_.Log(std::move(c4));
+  event_log_.Log(std::move(c5));
   event_log_.Log(std::make_unique<FakeEvent>());
   event_log_.StopLogging();
-  EXPECT_CALL(*encoder_ptr_,
-              OnEncode(Property(&RtcEvent::IsConfigEvent, true)));
+  time_controller_.AdvanceTime(TimeDelta::Zero());
+  InSequence s;
+  // Rewrite all config events in sequence on next restart.
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c1_ptr)));
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c2_ptr)));
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c3_ptr)));
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c4_ptr)));
+  EXPECT_CALL(*encoder_ptr_, OnEncode(Ref(*c5_ptr)));
   EXPECT_CALL(*encoder_ptr_,
               OnEncode(Property(&RtcEvent::IsConfigEvent, false)))
       .Times(0);
@@ -184,5 +231,23 @@ TEST_F(RtcEventLogImplTest, SchedulesWriteAfterOutputDurationPassed) {
   Mock::VerifyAndClearExpectations(encoder_ptr_);
 }
 
+TEST_F(RtcEventLogImplTest, DoNotDropEventsIfHistoryFullAfterStarted) {
+  const size_t kNumberOfEvents = 10 * kMaxEventsInHistory;
+
+  event_log_.StartLogging(std::make_unique<FakeOutput>(written_data_),
+                          kOutputPeriod.ms());
+  event_log_.Log(std::make_unique<FakeConfigEvent>());
+  for (size_t i = 0; i < kNumberOfEvents; i++) {
+    event_log_.Log(std::make_unique<FakeEvent>());
+  }
+  EXPECT_CALL(*encoder_ptr_,
+              OnEncode(Property(&RtcEvent::IsConfigEvent, true)));
+  EXPECT_CALL(*encoder_ptr_,
+              OnEncode(Property(&RtcEvent::IsConfigEvent, false)))
+      .Times(kNumberOfEvents);
+  time_controller_.AdvanceTime(kOutputPeriod);
+  Mock::VerifyAndClearExpectations(encoder_ptr_);
+}
+
 }  // namespace
 }  // namespace webrtc