diff --git a/video/video_send_stream.cc b/video/video_send_stream.cc
index c244d17077..8c0f8f6f72 100644
--- a/video/video_send_stream.cc
+++ b/video/video_send_stream.cc
@@ -244,7 +244,10 @@ void VideoSendStream::Stop() {
   RTC_DLOG(LS_INFO) << "VideoSendStream::Stop";
   running_ = false;
   rtp_transport_queue_->PostTask(ToQueuedTask(transport_queue_safety_, [this] {
-    transport_queue_safety_->SetNotAlive();
+    // As the stream can get re-used and implicitly restarted via changing
+    // the state of the active layers, we do not mark the
+    // `transport_queue_safety_` flag with `SetNotAlive()` here. That's only
+    // done when we stop permanently via `StopPermanentlyAndGetRtpStates()`.
     send_stream_.Stop();
   }));
 }
diff --git a/video/video_send_stream_tests.cc b/video/video_send_stream_tests.cc
index 8cb43136e5..09dbb70c67 100644
--- a/video/video_send_stream_tests.cc
+++ b/video/video_send_stream_tests.cc
@@ -90,6 +90,9 @@ enum : int {  // The first valid value is 1.
   kVideoTimingExtensionId,
 };
 
+// Readability convenience enum for `WaitBitrateChanged()`.
+enum class WaitUntil : bool { kZero = false, kNonZero = true };
+
 constexpr int64_t kRtcpIntervalMs = 1000;
 
 enum VideoFormat {
@@ -2153,7 +2156,7 @@ class StartStopBitrateObserver : public test::FakeEncoder {
     return encoder_init_.Wait(VideoSendStreamTest::kDefaultTimeoutMs);
   }
 
-  bool WaitBitrateChanged(bool non_zero) {
+  bool WaitBitrateChanged(WaitUntil until) {
     do {
       absl::optional<int> bitrate_kbps;
       {
@@ -2163,8 +2166,8 @@ class StartStopBitrateObserver : public test::FakeEncoder {
       if (!bitrate_kbps)
         continue;
 
-      if ((non_zero && *bitrate_kbps > 0) ||
-          (!non_zero && *bitrate_kbps == 0)) {
+      if ((until == WaitUntil::kNonZero && *bitrate_kbps > 0) ||
+          (until == WaitUntil::kZero && *bitrate_kbps == 0)) {
         return true;
       }
     } while (bitrate_changed_.Wait(VideoSendStreamTest::kDefaultTimeoutMs));
@@ -2211,15 +2214,15 @@ TEST_F(VideoSendStreamTest, VideoSendStreamStopSetEncoderRateToZero) {
 
   SendTask(RTC_FROM_HERE, task_queue(),
            [this]() { GetVideoSendStream()->Start(); });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(true));
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kNonZero));
 
   SendTask(RTC_FROM_HERE, task_queue(),
            [this]() { GetVideoSendStream()->Stop(); });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(false));
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kZero));
 
   SendTask(RTC_FROM_HERE, task_queue(),
            [this]() { GetVideoSendStream()->Start(); });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(true));
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kNonZero));
 
   SendTask(RTC_FROM_HERE, task_queue(), [this]() {
     DestroyStreams();
@@ -2268,7 +2271,7 @@ TEST_F(VideoSendStreamTest, VideoSendStreamUpdateActiveSimulcastLayers) {
     GetVideoSendStream()->UpdateActiveSimulcastLayers({true, true});
     EXPECT_TRUE(GetVideoSendStream()->started());
   });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(true));
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kNonZero));
 
   GetVideoEncoderConfig()->simulcast_layers[0].active = true;
   GetVideoEncoderConfig()->simulcast_layers[1].active = false;
@@ -2276,7 +2279,7 @@ TEST_F(VideoSendStreamTest, VideoSendStreamUpdateActiveSimulcastLayers) {
     GetVideoSendStream()->ReconfigureVideoEncoder(
         GetVideoEncoderConfig()->Copy());
   });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(true));
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kNonZero));
 
   // Turning off both simulcast layers should trigger a bitrate change of 0.
   GetVideoEncoderConfig()->simulcast_layers[0].active = false;
@@ -2285,7 +2288,7 @@ TEST_F(VideoSendStreamTest, VideoSendStreamUpdateActiveSimulcastLayers) {
     GetVideoSendStream()->UpdateActiveSimulcastLayers({false, false});
     EXPECT_FALSE(GetVideoSendStream()->started());
   });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(false));
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kZero));
 
   // Re-activating a layer should resume sending and trigger a bitrate change.
   GetVideoEncoderConfig()->simulcast_layers[0].active = true;
@@ -2293,12 +2296,23 @@ TEST_F(VideoSendStreamTest, VideoSendStreamUpdateActiveSimulcastLayers) {
     GetVideoSendStream()->UpdateActiveSimulcastLayers({true, false});
     EXPECT_TRUE(GetVideoSendStream()->started());
   });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(true));
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kNonZero));
 
-  // Stop and clean up.
-  SendTask(RTC_FROM_HERE, task_queue(),
-           [this]() { GetVideoSendStream()->Stop(); });
-  EXPECT_TRUE(encoder.WaitBitrateChanged(false));
+  // Stop the stream and make sure the bit rate goes to zero again.
+  SendTask(RTC_FROM_HERE, task_queue(), [this]() {
+    GetVideoSendStream()->Stop();
+    EXPECT_FALSE(GetVideoSendStream()->started());
+  });
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kZero));
+
+  // One last test to verify that after `Stop()` we can still implicitly start
+  // the stream if needed. This is what will happen when a send stream gets
+  // re-used. See crbug.com/1241213.
+  SendTask(RTC_FROM_HERE, task_queue(), [this]() {
+    GetVideoSendStream()->UpdateActiveSimulcastLayers({true, true});
+    EXPECT_TRUE(GetVideoSendStream()->started());
+  });
+  EXPECT_TRUE(encoder.WaitBitrateChanged(WaitUntil::kNonZero));
 
   SendTask(RTC_FROM_HERE, task_queue(), [this]() {
     DestroyStreams();
diff --git a/video/video_stream_encoder.cc b/video/video_stream_encoder.cc
index be611fad63..15855da1f2 100644
--- a/video/video_stream_encoder.cc
+++ b/video/video_stream_encoder.cc
@@ -1780,6 +1780,9 @@ void VideoStreamEncoder::SendKeyFrame() {
   TRACE_EVENT0("webrtc", "OnKeyFrameRequest");
   RTC_DCHECK(!next_frame_types_.empty());
 
+  if (!encoder_)
+    return;  // Shutting down.
+
   // TODO(webrtc:10615): Map keyframe request to spatial layer.
   std::fill(next_frame_types_.begin(), next_frame_types_.end(),
             VideoFrameType::kVideoFrameKey);