diff --git a/talk/app/webrtc/peerconnection.cc b/talk/app/webrtc/peerconnection.cc
index 369838174..d1338897d 100644
--- a/talk/app/webrtc/peerconnection.cc
+++ b/talk/app/webrtc/peerconnection.cc
@@ -39,6 +39,9 @@
 #include "talk/session/media/channelmanager.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/stringencode.h"
+#ifdef WEBRTC_CHROMIUM_BUILD
+#include "webrtc/system_wrappers/interface/field_trial.h"
+#endif
 
 namespace {
 
@@ -353,12 +356,19 @@ bool PeerConnection::DoInitialize(
                             cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
                             cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET;
   bool value;
+  // If IPv6 flag was specified, we'll not override it by experiment.
   if (FindConstraint(
-        constraints,
-        MediaConstraintsInterface::kEnableIPv6,
-        &value, NULL) && value) {
+          constraints, MediaConstraintsInterface::kEnableIPv6, &value, NULL)) {
+    if (value) {
+      portallocator_flags |= cricket::PORTALLOCATOR_ENABLE_IPV6;
+    }
+  }
+#ifdef WEBRTC_CHROMIUM_BUILD
+  else if (webrtc::field_trial::FindFullName("WebRTC-IPv6Default") ==
+           "Enabled") {
     portallocator_flags |= cricket::PORTALLOCATOR_ENABLE_IPV6;
   }
+#endif  // WEBRTC_CHROMIUM_BUILD
 
   port_allocator_->set_flags(portallocator_flags);
   // No step delay is used while allocating ports.