--- a/mobile/android/geckoview/build.gradle
+++ b/mobile/android/geckoview/build.gradle
@@ -72,22 +72,22 @@ android {
         main {
             java {
                 srcDir "${topsrcdir}/mobile/android/geckoview/src/thirdparty/java"
 
                 if (!mozconfig.substs.MOZ_ANDROID_HLS_SUPPORT) {
                     exclude 'com/google/android/exoplayer2/**'
                 }
 
-                // TODO: support WebRTC.
-                // if (mozconfig.substs.MOZ_WEBRTC) {
-                //     srcDir "${topsrcdir}/media/webrtc/trunk/webrtc/modules/audio_device/android/java/src"
-                //     srcDir "${topsrcdir}/media/webrtc/trunk/webrtc/modules/video_capture/android/java/src"
-                //     srcDir "${topsrcdir}/media/webrtc/trunk/webrtc/modules/video_render/android/java/src"
-                // }
+                if (mozconfig.substs.MOZ_WEBRTC) {
+                    srcDir "${topsrcdir}/media/webrtc/trunk/webrtc/base/java/src/org/webrtc/"
+                    srcDir "${topsrcdir}/media/webrtc/trunk/webrtc/modules/audio_device/android/java/src"
+                    srcDir "${topsrcdir}/media/webrtc/trunk/webrtc/modules/video_capture/android/java/src"
+                    srcDir "${topsrcdir}/media/webrtc/trunk/webrtc/modules/video_render/android/java/src"
+                }
 
                 // TODO: don't use AppConstants.
                 srcDir "${project.buildDir}/generated/source/preprocessed_code" // See syncPreprocessedCode.
             }
 
             assets {
             }
         }