diff --git a/src/jni/rtp/AudioGroup.cpp b/src/jni/rtp/AudioGroup.cpp
index 7bba14d..eb3b18f 100644
--- a/src/jni/rtp/AudioGroup.cpp
+++ b/src/jni/rtp/AudioGroup.cpp
@@ -826,13 +826,13 @@
     track->setCallerName("rtp");
     record->setCallerName("rtp");
     if (track->set(AUDIO_STREAM_VOICE_CALL, sampleRate, AUDIO_FORMAT_PCM_16_BIT,
-                AUDIO_CHANNEL_OUT_MONO, output, AUDIO_OUTPUT_FLAG_NONE, NULL /*callback_t*/,
-                NULL /*user*/, 0 /*notificationFrames*/, 0 /*sharedBuffer*/,
+                AUDIO_CHANNEL_OUT_MONO, output, AUDIO_OUTPUT_FLAG_NONE, nullptr /*callback*/,
+                0 /*notificationFrames*/, 0 /*sharedBuffer*/,
                 false /*threadCanCallJava*/, AUDIO_SESSION_ALLOCATE,
                 AudioTrack::TRANSFER_OBTAIN) != NO_ERROR ||
             record->set(AUDIO_SOURCE_VOICE_COMMUNICATION, sampleRate, AUDIO_FORMAT_PCM_16_BIT,
-                AUDIO_CHANNEL_IN_MONO, input, NULL /*callback_t*/, NULL /*user*/,
-                0 /*notificationFrames*/, false /*threadCanCallJava*/, AUDIO_SESSION_ALLOCATE,
+                AUDIO_CHANNEL_IN_MONO, input, nullptr /*callback*/, 0 /*notificationFrames*/,
+                false /*threadCanCallJava*/, AUDIO_SESSION_ALLOCATE,
                 AudioRecord::TRANSFER_OBTAIN) != NO_ERROR) {
         ALOGE("cannot initialize audio device");
         return false;