diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_sender.cc b/webrtc/modules/rtp_rtcp/source/rtcp_sender.cc
index 57c77a9..066b179 100644
--- a/webrtc/modules/rtp_rtcp/source/rtcp_sender.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_sender.cc
@@ -593,31 +593,18 @@
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
 RTCPSender::BuildResult RTCPSender::BuildSLI(RtcpContext* ctx) {
-  // sanity
-  if (ctx->position + 16 >= IP_PACKET_SIZE)
+  rtcp::Sli sli;
+  sli.From(ssrc_);
+  sli.To(remote_ssrc_);
+  // Crop picture id to 6 least significant bits.
+  sli.WithPictureId(ctx->picture_id & 0x3F);
+  sli.WithFirstMb(0);
+  sli.WithNumberOfMb(0x1FFF);  // 13 bits, only ones for now.
+
+  PacketBuiltCallback callback(ctx);
+  if (!callback.BuildPacket(sli))
     return BuildResult::kTruncated;
 
-  // add slice loss indicator
-  uint8_t FMT = 2;
-  *ctx->AllocateData(1) = 0x80 + FMT;
-  *ctx->AllocateData(1) = 206;
-
-  // Used fixed length of 3
-  *ctx->AllocateData(1) = 0;
-  *ctx->AllocateData(1) = 3;
-
-  // Add our own SSRC
-  ByteWriter<uint32_t>::WriteBigEndian(ctx->AllocateData(4), ssrc_);
-
-  // Add the remote SSRC
-  ByteWriter<uint32_t>::WriteBigEndian(ctx->AllocateData(4), remote_ssrc_);
-
-  // Add first, number & picture ID 6 bits
-  // first  = 0, 13 - bits
-  // number = 0x1fff, 13 - bits only ones for now
-  uint32_t sliField = (0x1fff << 6) + (0x3f & ctx->picture_id);
-  ByteWriter<uint32_t>::WriteBigEndian(ctx->AllocateData(4), sliField);
-
   return BuildResult::kSuccess;
 }
 
diff --git a/webrtc/modules/rtp_rtcp/test/testAPI/test_api_rtcp.cc b/webrtc/modules/rtp_rtcp/test/testAPI/test_api_rtcp.cc
index 741b7ac..4fc89a9 100644
--- a/webrtc/modules/rtp_rtcp/test/testAPI/test_api_rtcp.cc
+++ b/webrtc/modules/rtp_rtcp/test/testAPI/test_api_rtcp.cc
@@ -23,6 +23,7 @@
 using namespace webrtc;
 
 const uint64_t kTestPictureId = 12345678;
+const uint8_t kSliPictureId = 156;
 
 class RtcpCallback : public RtcpIntraFrameObserver {
  public:
@@ -38,7 +39,7 @@
   };
   virtual void OnReceivedSLI(uint32_t ssrc,
                              uint8_t pictureId) {
-    EXPECT_EQ(28, pictureId);
+    EXPECT_EQ(kSliPictureId & 0x3f, pictureId);
   };
   virtual void OnReceivedRPSI(uint32_t ssrc,
                               uint64_t pictureId) {
@@ -204,7 +205,7 @@
 
 TEST_F(RtpRtcpRtcpTest, RTCP_PLI_RPSI) {
   EXPECT_EQ(0, module1->SendRTCPReferencePictureSelection(kTestPictureId));
-  EXPECT_EQ(0, module1->SendRTCPSliceLossIndication(156));
+  EXPECT_EQ(0, module1->SendRTCPSliceLossIndication(kSliPictureId));
 }
 
 TEST_F(RtpRtcpRtcpTest, RTCP_CNAME) {