diff --git a/include/sora/sora_video_decoder_factory.h b/include/sora/sora_video_decoder_factory.h
index 44e7249a..7518e332 100644
--- a/include/sora/sora_video_decoder_factory.h
+++ b/include/sora/sora_video_decoder_factory.h
@@ -5,7 +5,7 @@
 #include <vector>
 
 // WebRTC
-#include <api/environment/environment.h>
+#include <api/environment/environment_factory.h>
 #include <api/video/video_codec_type.h>
 #include <api/video_codecs/video_decoder_factory.h>
 
@@ -64,12 +64,12 @@ class SoraVideoDecoderFactory : public webrtc::VideoDecoderFactory {
 
 // ハードウェアデコーダを出来るだけ使おうとして、見つからなければソフトウェアデコーダを使う設定を返す
 SoraVideoDecoderFactoryConfig GetDefaultVideoDecoderFactoryConfig(
-    webrtc::Environment& env,
     std::shared_ptr<CudaContext> cuda_context = nullptr,
-    void* jni_env = nullptr);
+    void* jni_env = nullptr,
+    webrtc::Environment env = webrtc::CreateEnvironment());
 // ソフトウェアデコーダのみを使う設定を返す
 SoraVideoDecoderFactoryConfig GetSoftwareOnlyVideoDecoderFactoryConfig(
-    webrtc::Environment& env);
+    webrtc::Environment env = webrtc::CreateEnvironment());
 
 }  // namespace sora
 
diff --git a/src/sora_client_context.cpp b/src/sora_client_context.cpp
index 7c65f1c0..91ed6dfa 100644
--- a/src/sora_client_context.cpp
+++ b/src/sora_client_context.cpp
@@ -105,8 +105,8 @@ std::shared_ptr<SoraClientContext> SoraClientContext::Create(
     auto env = webrtc::CreateEnvironment();
 
     auto config = c->config_.use_hardware_encoder
-                      ? sora::GetDefaultVideoDecoderFactoryConfig(
-                            env, cuda_context, jni_env)
+                      ? sora::GetDefaultVideoDecoderFactoryConfig(cuda_context,
+                                                                  jni_env, env)
                       : sora::GetSoftwareOnlyVideoDecoderFactoryConfig(env);
     dependencies.video_decoder_factory =
         absl::make_unique<sora::SoraVideoDecoderFactory>(std::move(config));
diff --git a/src/sora_peer_connection_factory.cpp b/src/sora_peer_connection_factory.cpp
index 1c427fa7..643aacbe 100644
--- a/src/sora_peer_connection_factory.cpp
+++ b/src/sora_peer_connection_factory.cpp
@@ -14,7 +14,7 @@ class PeerConnectionFactoryWithContext : public webrtc::PeerConnectionFactory {
   PeerConnectionFactoryWithContext(
       webrtc::PeerConnectionFactoryDependencies dependencies)
       : PeerConnectionFactoryWithContext(
-            // TODO(enm10k): environment を外部から設定できるようにする
+            // SDK の外部から webrtc::Environment を設定したくなるまで、ここで初期化する
             webrtc::ConnectionContext::Create(webrtc::CreateEnvironment(),
                                               &dependencies),
             &dependencies) {}
diff --git a/src/sora_video_decoder_factory.cpp b/src/sora_video_decoder_factory.cpp
index cf916144..e747b6f2 100644
--- a/src/sora_video_decoder_factory.cpp
+++ b/src/sora_video_decoder_factory.cpp
@@ -109,9 +109,9 @@ std::unique_ptr<webrtc::VideoDecoder> SoraVideoDecoderFactory::Create(
 }
 
 SoraVideoDecoderFactoryConfig GetDefaultVideoDecoderFactoryConfig(
-    webrtc::Environment& env,
     std::shared_ptr<CudaContext> cuda_context,
-    void* jni_env) {
+    void* jni_env,
+    webrtc::Environment env) {
   auto config = GetSoftwareOnlyVideoDecoderFactoryConfig(env);
 
 #if defined(__APPLE__)
@@ -252,7 +252,7 @@ SoraVideoDecoderFactoryConfig GetDefaultVideoDecoderFactoryConfig(
 }
 
 SoraVideoDecoderFactoryConfig GetSoftwareOnlyVideoDecoderFactoryConfig(
-    webrtc::Environment& env) {
+    webrtc::Environment env) {
   SoraVideoDecoderFactoryConfig config;
   config.decoders.push_back(VideoDecoderConfig(
       webrtc::kVideoCodecVP8,