diff --git a/modules/audio_coding/acm2/acm_receiver.h b/modules/audio_coding/acm2/acm_receiver.h
index 8d54cf7b33..f07f8a951c 100644
--- a/modules/audio_coding/acm2/acm_receiver.h
+++ b/modules/audio_coding/acm2/acm_receiver.h
@@ -175,13 +175,12 @@ class AcmReceiver {
   // Enable NACK and set the maximum size of the NACK list. If NACK is already
   // enabled then the maximum NACK list size is modified accordingly.
   //
-  // Input:
-  //    -max_nack_list_size  : maximum NACK list size
-  //                           should be positive (none zero) and less than or
-  //                           equal to |Nack::kNackListSizeLimit|
-  // Return value
-  //                         : 0 if succeeded.
-  //                          -1 if failed
+  // If the sequence number of last received packet is N, the sequence numbers
+  // of NACK list are in the range of [N - |max_nack_list_size|, N).
+  //
+  // |max_nack_list_size| should be positive (none zero) and less than or
+  // equal to |Nack::kNackListSizeLimit|. Otherwise, No change is applied and -1
+  // is returned. 0 is returned at success.
   //
   int EnableNack(size_t max_nack_list_size);
 
@@ -189,11 +188,13 @@ class AcmReceiver {
   void DisableNack();
 
   //
-  // Get a list of packets to be retransmitted.
+  // Get a list of packets to be retransmitted. |round_trip_time_ms| is an
+  // estimate of the round-trip-time (in milliseconds). Missing packets which
+  // will be playout in a shorter time than the round-trip-time (with respect
+  // to the time this API is called) will not be included in the list.
   //
-  // Input:
-  //    -round_trip_time_ms : estimate of the round-trip-time (in milliseconds).
-  // Return value           : list of packets to be retransmitted.
+  // Negative |round_trip_time_ms| results is an error message and empty list
+  // is returned.
   //
   std::vector<uint16_t> GetNackList(int64_t round_trip_time_ms) const;
 
diff --git a/modules/audio_coding/acm2/audio_coding_module.cc b/modules/audio_coding/acm2/audio_coding_module.cc
index 6c0e31edc2..b0421f50d2 100644
--- a/modules/audio_coding/acm2/audio_coding_module.cc
+++ b/modules/audio_coding/acm2/audio_coding_module.cc
@@ -118,12 +118,6 @@ class AudioCodingModuleImpl final : public AudioCodingModule {
 
   int GetNetworkStatistics(NetworkStatistics* statistics) override;
 
-  int EnableNack(size_t max_nack_list_size) override;
-
-  void DisableNack() override;
-
-  std::vector<uint16_t> GetNackList(int64_t round_trip_time_ms) const override;
-
   void GetDecodingCallStatistics(AudioDecodingCallStats* stats) const override;
 
   ANAStats GetANAStats() const override;
@@ -722,19 +716,6 @@ bool AudioCodingModuleImpl::HaveValidEncoder(const char* caller_name) const {
   return true;
 }
 
-int AudioCodingModuleImpl::EnableNack(size_t max_nack_list_size) {
-  return receiver_.EnableNack(max_nack_list_size);
-}
-
-void AudioCodingModuleImpl::DisableNack() {
-  receiver_.DisableNack();
-}
-
-std::vector<uint16_t> AudioCodingModuleImpl::GetNackList(
-    int64_t round_trip_time_ms) const {
-  return receiver_.GetNackList(round_trip_time_ms);
-}
-
 void AudioCodingModuleImpl::GetDecodingCallStatistics(
     AudioDecodingCallStats* call_stats) const {
   receiver_.GetDecodingCallStatistics(call_stats);
diff --git a/modules/audio_coding/include/audio_coding_module.h b/modules/audio_coding/include/audio_coding_module.h
index 8d0e9eee38..177ce3bc30 100644
--- a/modules/audio_coding/include/audio_coding_module.h
+++ b/modules/audio_coding/include/audio_coding_module.h
@@ -341,34 +341,6 @@ class AudioCodingModule {
   virtual int32_t GetNetworkStatistics(
       NetworkStatistics* network_statistics) = 0;
 
-  //
-  // Enable NACK and set the maximum size of the NACK list. If NACK is already
-  // enable then the maximum NACK list size is modified accordingly.
-  //
-  // If the sequence number of last received packet is N, the sequence numbers
-  // of NACK list are in the range of [N - |max_nack_list_size|, N).
-  //
-  // |max_nack_list_size| should be positive (none zero) and less than or
-  // equal to |Nack::kNackListSizeLimit|. Otherwise, No change is applied and -1
-  // is returned. 0 is returned at success.
-  //
-  virtual int EnableNack(size_t max_nack_list_size) = 0;
-
-  // Disable NACK.
-  virtual void DisableNack() = 0;
-
-  //
-  // Get a list of packets to be retransmitted. |round_trip_time_ms| is an
-  // estimate of the round-trip-time (in milliseconds). Missing packets which
-  // will be playout in a shorter time than the round-trip-time (with respect
-  // to the time this API is called) will not be included in the list.
-  //
-  // Negative |round_trip_time_ms| results is an error message and empty list
-  // is returned.
-  //
-  virtual std::vector<uint16_t> GetNackList(
-      int64_t round_trip_time_ms) const = 0;
-
   virtual void GetDecodingCallStatistics(
       AudioDecodingCallStats* call_stats) const = 0;