--- a/media/webrtc/signaling/src/jsep/JsepSessionImpl.cpp
+++ b/media/webrtc/signaling/src/jsep/JsepSessionImpl.cpp
@@ -2083,36 +2083,37 @@ JsepSessionImpl::SetupDefaultCodecs()
                                     "PCMA",
                                     8000,
                                     1,
                                     8000 / 50,   // frequency / 50
                                     8 * 8000 * 1 // 8 * frequency * channels
                                     ));
 
   // Supported video codecs.
+  // Note: order here implies priority for building offers!
+  JsepVideoCodecDescription* vp9 = new JsepVideoCodecDescription(
+      "121",
+      "VP9",
+      90000
+      );
+  // Defaults for mandatory params
+  vp9->mConstraints.maxFs = 12288; // Enough for 2048x1536
+  vp9->mConstraints.maxFps = 60;
+  mSupportedCodecs.values.push_back(vp9);
+
   JsepVideoCodecDescription* vp8 = new JsepVideoCodecDescription(
       "120",
       "VP8",
       90000
       );
   // Defaults for mandatory params
   vp8->mConstraints.maxFs = 12288; // Enough for 2048x1536
   vp8->mConstraints.maxFps = 60;
   mSupportedCodecs.values.push_back(vp8);
 
-  JsepVideoCodecDescription* vp9 = new JsepVideoCodecDescription(
-      "121",
-      "VP9",
-      90000
-      );
-  // Defaults for mandatory params
-  vp9->mConstraints.maxFs = 12288; // Enough for 2048x1536
-  vp9->mConstraints.maxFps = 60;
-  mSupportedCodecs.values.push_back(vp9);
-
   JsepVideoCodecDescription* h264_1 = new JsepVideoCodecDescription(
       "126",
       "H264",
       90000
       );
   h264_1->mPacketizationMode = 1;
   // Defaults for mandatory params
   h264_1->mProfileLevelId = 0x42E00D;