diff --git a/webrtc/modules/rtp_rtcp/source/rtp_utility.cc b/webrtc/modules/rtp_rtcp/source/rtp_utility.cc
index 37df7d254a..08743b3b2a 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_utility.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_utility.cc
@@ -45,6 +45,11 @@ namespace webrtc {
 
 namespace ModuleRTPUtility {
 
+enum {
+  kRtcpMinHeaderLength = 4,
+  kRtcpExpectedVersion = 2
+};
+
 /*
  * Time routines.
  */
@@ -269,11 +274,18 @@ bool RTPHeaderParser::RTCP() const {
   * FMT 15:    Application layer FB message
   */
 
+  const ptrdiff_t length = _ptrRTPDataEnd - _ptrRTPDataBegin;
+  if (length < kRtcpMinHeaderLength) {
+    return false;
+  }
+
+  const WebRtc_UWord8 V  = _ptrRTPDataBegin[0] >> 6;
+  if (V != kRtcpExpectedVersion) {
+    return false;
+  }
+
   const WebRtc_UWord8  payloadType = _ptrRTPDataBegin[1];
-
   bool RTCP = false;
-
-  // check if this is a RTCP packet
   switch (payloadType) {
     case 192:
       RTCP = true;