diff --git a/webrtc/modules/audio_coding/main/acm2/acm_opus.cc b/webrtc/modules/audio_coding/main/acm2/acm_opus.cc
index c00a9203a9..5830f6b40d 100644
--- a/webrtc/modules/audio_coding/main/acm2/acm_opus.cc
+++ b/webrtc/modules/audio_coding/main/acm2/acm_opus.cc
@@ -140,6 +140,20 @@ int16_t ACMOpus::InternalInitEncoder(WebRtcACMCodecParams* codec_params) {
   // Store bitrate.
   bitrate_ = codec_params->codec_inst.rate;
 
+  // TODO(tlegrand): Remove this code when we have proper APIs to set the
+  // complexity at a higher level.
+#if defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS) || defined(WEBRTC_ARCH_ARM)
+  // If we are on Android, iOS and/or ARM, use a lower complexity setting as
+  // default, to save encoder complexity.
+  const int kOpusComplexity5 = 5;
+  WebRtcOpus_SetComplexity(encoder_inst_ptr_, kOpusComplexity5);
+  if (ret < 0) {
+     WEBRTC_TRACE(webrtc::kTraceError, webrtc::kTraceAudioCoding, unique_id_,
+                  "Setting complexity failed for Opus");
+     return ret;
+   }
+#endif
+
   return 0;
 }
 
diff --git a/webrtc/modules/audio_coding/main/test/opus_test.cc b/webrtc/modules/audio_coding/main/test/opus_test.cc
index 5eec83b7f5..027aeb045c 100644
--- a/webrtc/modules/audio_coding/main/test/opus_test.cc
+++ b/webrtc/modules/audio_coding/main/test/opus_test.cc
@@ -227,6 +227,15 @@ void OpusTest::Run(TestPackStereo* channel, int channels, int bitrate,
   EXPECT_EQ(0, WebRtcOpus_SetBitRate(opus_mono_encoder_, bitrate));
   EXPECT_EQ(0, WebRtcOpus_SetBitRate(opus_stereo_encoder_, bitrate));
 
+#if defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS) || defined(WEBRTC_ARCH_ARM)
+  // If we are on Android, iOS and/or ARM, use a lower complexity setting as
+  // default.
+  const int kOpusComplexity5 = 5;
+  EXPECT_EQ(0, WebRtcOpus_SetComplexity(opus_mono_encoder_, kOpusComplexity5));
+  EXPECT_EQ(0, WebRtcOpus_SetComplexity(opus_stereo_encoder_,
+                                        kOpusComplexity5));
+#endif
+
   // Make sure the runtime is less than 60 seconds to pass Android test.
   for (size_t audio_length = 0; audio_length < 10000; audio_length += 10) {
     bool lost_packet = false;