diff --git a/test/fuzzers/audio_processing_configs_fuzzer.cc b/test/fuzzers/audio_processing_configs_fuzzer.cc
index 8dd0e29634..57699dd5b3 100644
--- a/test/fuzzers/audio_processing_configs_fuzzer.cc
+++ b/test/fuzzers/audio_processing_configs_fuzzer.cc
@@ -122,6 +122,7 @@ std::unique_ptr<AudioProcessing> CreateApm(test::FuzzDataHelper* fuzz_data,
 #endif
 
   webrtc::AudioProcessing::Config apm_config;
+  apm_config.pipeline.experimental_multi_channel = true;
   apm_config.echo_canceller.enabled = use_aec || use_aecm;
   apm_config.echo_canceller.mobile_mode = use_aecm;
   apm_config.residual_echo_detector.enabled = red;
diff --git a/test/fuzzers/audio_processing_fuzzer_helper.cc b/test/fuzzers/audio_processing_fuzzer_helper.cc
index 5d7ea4c807..eb2e0e8960 100644
--- a/test/fuzzers/audio_processing_fuzzer_helper.cc
+++ b/test/fuzzers/audio_processing_fuzzer_helper.cc
@@ -71,12 +71,14 @@ void GenerateFixedFrame(test::FuzzDataHelper* fuzz_data,
 void FuzzAudioProcessing(test::FuzzDataHelper* fuzz_data,
                          std::unique_ptr<AudioProcessing> apm) {
   AudioFrame fixed_frame;
-  std::array<float, 480> float_frame1;
-  std::array<float, 480> float_frame2;
-  std::array<float* const, 2> float_frame_ptrs = {
-      &float_frame1[0],
-      &float_frame2[0],
-  };
+  // Normal usage is up to 8 channels. Allowing to fuzz one beyond this allows
+  // us to catch implicit assumptions about normal usage.
+  constexpr int kMaxNumChannels = 9;
+  std::array<std::array<float, 480>, kMaxNumChannels> float_frames;
+  std::array<float*, kMaxNumChannels> float_frame_ptrs;
+  for (int i = 0; i < kMaxNumChannels; ++i) {
+    float_frame_ptrs[i] = float_frames[i].data();
+  }
   float* const* ptr_to_float_frames = &float_frame_ptrs[0];
 
   using Rate = AudioProcessing::NativeRate;
@@ -94,7 +96,6 @@ void FuzzAudioProcessing(test::FuzzDataHelper* fuzz_data,
     const auto output_rate =
         static_cast<size_t>(fuzz_data->SelectOneOf(rate_kinds));
 
-    const int num_channels = fuzz_data->ReadOrDefaultValue(true) ? 2 : 1;
     const uint8_t stream_delay = fuzz_data->ReadOrDefaultValue<uint8_t>(0);
 
     // API call needed for AEC-2 and AEC-m to run.
@@ -110,6 +111,9 @@ void FuzzAudioProcessing(test::FuzzDataHelper* fuzz_data,
     // Fill the arrays with audio samples from the data.
     int apm_return_code = AudioProcessing::Error::kNoError;
     if (is_float) {
+      const int num_channels =
+          fuzz_data->ReadOrDefaultValue<uint8_t>(1) % kMaxNumChannels;
+
       GenerateFloatFrame(fuzz_data, input_rate, num_channels,
                          ptr_to_float_frames);
       if (is_capture) {
@@ -122,6 +126,7 @@ void FuzzAudioProcessing(test::FuzzDataHelper* fuzz_data,
             StreamConfig(output_rate, 1), ptr_to_float_frames);
       }
     } else {
+      const int num_channels = fuzz_data->ReadOrDefaultValue(true) ? 2 : 1;
       GenerateFixedFrame(fuzz_data, input_rate, num_channels, &fixed_frame);
 
       if (is_capture) {