diff --git a/webrtc/modules/video_coding/main/source/jitter_buffer.cc b/webrtc/modules/video_coding/main/source/jitter_buffer.cc
index ac3db7461..bef7bb59e 100644
--- a/webrtc/modules/video_coding/main/source/jitter_buffer.cc
+++ b/webrtc/modules/video_coding/main/source/jitter_buffer.cc
@@ -844,6 +844,9 @@ uint16_t VCMJitterBuffer::EstimatedLowSequenceNumber(
   assert(frame.GetLowSeqNum() >= 0);
   if (frame.HaveFirstPacket())
     return frame.GetLowSeqNum();
+
+  // This estimate is not accurate if more than one packet with lower sequence
+  // number is lost.
   return frame.GetLowSeqNum() - 1;
 }
 
@@ -895,6 +898,8 @@ uint16_t* VCMJitterBuffer::GetNackList(uint16_t* nack_list_size,
       } else {
         // Skip to the last key frame. If it's incomplete we will start
         // NACKing it.
+        // Note that the estimated low sequence number is correct for VP8
+        // streams because only the first packet of a key frame is marked.
         last_decoded_state_.Reset();
         DropPacketsFromNackList(EstimatedLowSequenceNumber(**rit));
       }
@@ -1129,6 +1134,8 @@ bool VCMJitterBuffer::RecycleFramesUntilKeyFrame() {
     if (it != frame_list_.end() && (*it)->FrameType() == kVideoFrameKey) {
       // Reset last decoded state to make sure the next frame decoded is a key
       // frame, and start NACKing from here.
+      // Note that the estimated low sequence number is correct for VP8
+      // streams because only the first packet of a key frame is marked.
       last_decoded_state_.Reset();
       DropPacketsFromNackList(EstimatedLowSequenceNumber(**it));
       return true;
diff --git a/webrtc/modules/video_coding/main/source/jitter_buffer_unittest.cc b/webrtc/modules/video_coding/main/source/jitter_buffer_unittest.cc
index ec3e59d25..e1fa12f4f 100644
--- a/webrtc/modules/video_coding/main/source/jitter_buffer_unittest.cc
+++ b/webrtc/modules/video_coding/main/source/jitter_buffer_unittest.cc
@@ -1674,6 +1674,32 @@ TEST_F(TestJitterBufferNack, UseNackToRecoverFirstKeyFrame) {
   EXPECT_EQ(packet.seqNum, list[0]);
 }
 
+TEST_F(TestJitterBufferNack, UseNackToRecoverFirstKeyFrameSecondInQueue) {
+  VCMPacket packet;
+  stream_generator_->Init(0, 0, clock_->TimeInMilliseconds());
+  // First frame is delta.
+  stream_generator_->GenerateFrame(kVideoFrameDelta, 3, 0,
+                                   clock_->TimeInMilliseconds());
+  EXPECT_EQ(kFirstPacket, InsertPacketAndPop(0));
+  // Drop second packet in frame.
+  ASSERT_TRUE(stream_generator_->PopPacket(&packet, 0));
+  EXPECT_EQ(kIncomplete, InsertPacketAndPop(0));
+  // Second frame is key.
+  stream_generator_->GenerateFrame(kVideoFrameKey, 3, 0,
+                                   clock_->TimeInMilliseconds() + 10);
+  EXPECT_EQ(kFirstPacket, InsertPacketAndPop(0));
+  // Drop second packet in frame.
+  EXPECT_EQ(kIncomplete, InsertPacketAndPop(1));
+  EXPECT_FALSE(DecodeCompleteFrame());
+  uint16_t nack_list_size = 0;
+  bool extended = false;
+  uint16_t* list = jitter_buffer_->GetNackList(&nack_list_size, &extended);
+  EXPECT_EQ(1, nack_list_size);
+  ASSERT_TRUE(list != NULL);
+  stream_generator_->GetPacket(&packet, 0);
+  EXPECT_EQ(packet.seqNum, list[0]);
+}
+
 TEST_F(TestJitterBufferNack, NormalOperation) {
   EXPECT_EQ(kNack, jitter_buffer_->nack_mode());
   jitter_buffer_->DecodeWithErrors(true);