diff --git a/api/audio/BUILD.gn b/api/audio/BUILD.gn
index 9ea145bc2c..270a06579c 100644
--- a/api/audio/BUILD.gn
+++ b/api/audio/BUILD.gn
@@ -89,4 +89,7 @@ rtc_source_set("echo_control") {
   sources = [
     "echo_control.h",
   ]
+  deps = [
+    "../../rtc_base:checks",
+  ]
 }
diff --git a/api/audio/echo_canceller3_factory.cc b/api/audio/echo_canceller3_factory.cc
index cff75dea5a..7df43b3fd4 100644
--- a/api/audio/echo_canceller3_factory.cc
+++ b/api/audio/echo_canceller3_factory.cc
@@ -21,9 +21,16 @@ EchoCanceller3Factory::EchoCanceller3Factory(const EchoCanceller3Config& config)
     : config_(config) {}
 
 std::unique_ptr<EchoControl> EchoCanceller3Factory::Create(int sample_rate_hz) {
-  return std::make_unique<EchoCanceller3>(config_, sample_rate_hz,
-                                          /*num_render_channels=*/1,
-                                          /*num_capture_channels=*/1);
+  return Create(sample_rate_hz, /*num_render_channels=*/1,
+                /*num_capture_channels=*/1);
+}
+
+std::unique_ptr<EchoControl> EchoCanceller3Factory::Create(
+    int sample_rate_hz,
+    int num_render_channels,
+    int num_capture_channels) {
+  return std::make_unique<EchoCanceller3>(
+      config_, sample_rate_hz, num_render_channels, num_capture_channels);
 }
 
 }  // namespace webrtc
diff --git a/api/audio/echo_canceller3_factory.h b/api/audio/echo_canceller3_factory.h
index 3fa6922a3b..43f49a1b66 100644
--- a/api/audio/echo_canceller3_factory.h
+++ b/api/audio/echo_canceller3_factory.h
@@ -29,9 +29,15 @@ class RTC_EXPORT EchoCanceller3Factory : public EchoControlFactory {
   explicit EchoCanceller3Factory(const EchoCanceller3Config& config);
 
   // Creates an EchoCanceller3 running at the specified sampling rate using a
-  // mono setup
+  // mono setup.
   std::unique_ptr<EchoControl> Create(int sample_rate_hz) override;
 
+  // Creates an EchoCanceller3 running at the specified sampling rate using a
+  // multichannel setup.
+  std::unique_ptr<EchoControl> Create(int sample_rate_hz,
+                                      int num_render_channels,
+                                      int num_capture_channels) override;
+
  private:
   const EchoCanceller3Config config_;
 };
diff --git a/api/audio/echo_control.h b/api/audio/echo_control.h
index d16c1ff086..11ba989d7a 100644
--- a/api/audio/echo_control.h
+++ b/api/audio/echo_control.h
@@ -13,6 +13,8 @@
 
 #include <memory>
 
+#include "rtc_base/checks.h"
+
 namespace webrtc {
 
 class AudioBuffer;
@@ -51,6 +53,14 @@ class EchoControl {
 class EchoControlFactory {
  public:
   virtual std::unique_ptr<EchoControl> Create(int sample_rate_hz) = 0;
+  // TODO(peah): Make pure virtual.
+  virtual std::unique_ptr<EchoControl> Create(int sample_rate_hz,
+                                              int num_render_channels,
+                                              int num_capture_channels) {
+    RTC_NOTREACHED();
+    return nullptr;
+  }
+
   virtual ~EchoControlFactory() = default;
 };
 }  // namespace webrtc
diff --git a/modules/audio_processing/audio_processing_impl.cc b/modules/audio_processing/audio_processing_impl.cc
index 4573aedf98..fb46e04577 100644
--- a/modules/audio_processing/audio_processing_impl.cc
+++ b/modules/audio_processing/audio_processing_impl.cc
@@ -1783,8 +1783,8 @@ void AudioProcessingImpl::InitializeEchoController() {
   if (use_echo_controller) {
     // Create and activate the echo controller.
     if (echo_control_factory_) {
-      submodules_.echo_controller =
-          echo_control_factory_->Create(proc_sample_rate_hz());
+      submodules_.echo_controller = echo_control_factory_->Create(
+          proc_sample_rate_hz(), num_reverse_channels(), num_proc_channels());
     } else {
       submodules_.echo_controller = std::make_unique<EchoCanceller3>(
           EchoCanceller3Config(), proc_sample_rate_hz(), num_reverse_channels(),
diff --git a/modules/audio_processing/audio_processing_impl_unittest.cc b/modules/audio_processing/audio_processing_impl_unittest.cc
index b4f78e544e..5a2391b510 100644
--- a/modules/audio_processing/audio_processing_impl_unittest.cc
+++ b/modules/audio_processing/audio_processing_impl_unittest.cc
@@ -54,6 +54,12 @@ class MockEchoControlFactory : public EchoControlFactory {
   // Returns a pointer to the next MockEchoControl that this factory creates.
   MockEchoControl* GetNext() const { return next_mock_.get(); }
   std::unique_ptr<EchoControl> Create(int sample_rate_hz) override {
+    RTC_NOTREACHED();
+    return nullptr;
+  }
+  std::unique_ptr<EchoControl> Create(int sample_rate_hz,
+                                      int num_render_channels,
+                                      int num_capture_channels) override {
     std::unique_ptr<EchoControl> mock = std::move(next_mock_);
     next_mock_ = std::make_unique<MockEchoControl>();
     return mock;
diff --git a/modules/audio_processing/audio_processing_unittest.cc b/modules/audio_processing/audio_processing_unittest.cc
index 094823de41..06dbba7a5b 100644
--- a/modules/audio_processing/audio_processing_unittest.cc
+++ b/modules/audio_processing/audio_processing_unittest.cc
@@ -2430,8 +2430,8 @@ class MyEchoControlFactory : public EchoControlFactory {
   }
 
   std::unique_ptr<EchoControl> Create(int sample_rate_hz,
-                                      size_t num_render_channels,
-                                      size_t num_capture_channels) {
+                                      int num_render_channels,
+                                      int num_capture_channels) {
     return Create(sample_rate_hz);
   }
 };