diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index 41b45aa9f5..9c750f0692 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -253,6 +253,9 @@ class AudioProcessing : public rtc::RefCountInterface {
     struct EchoCanceller {
       bool enabled = false;
       bool mobile_mode = false;
+      // Recommended not to use. Will be removed in the future.
+      // APM components are not fine-tuned for legacy suppression levels.
+      bool legacy_moderate_suppression_level = false;
     } echo_canceller;
 
     struct ResidualEchoDetector {