diff --git a/CHANGES.md b/CHANGES.md
index ed631977..22223dbe 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -11,6 +11,15 @@
 
 ## develop
 
+## 2021.2.3
+
+- [UPDATE] cmake を 3.20.0 に上げる
+    - @melpon @voluntas
+- [FIX] Jetson で HW エンコーダー指定時に、初期化タイミングによって、まれにセグフォが発生する問題を修正する
+    - @enm10k
+
+## 2021.2.2
+
 - [UPDATE] cmake を 3.19.6 に上げる
     - @voluntas
 - [UPDATE] `libwebrtc` を `M89.4389@{#7}` に上げる
diff --git a/VERSION b/VERSION
index 5f12cdc0..92a1da34 100644
--- a/VERSION
+++ b/VERSION
@@ -1,7 +1,7 @@
-MOMO_VERSION=2021.2.2
+MOMO_VERSION=2021.2.3
 WEBRTC_BUILD_VERSION=89.4389.7.0
 BOOST_VERSION=1.75.0
 CLI11_VERSION=1.9.1
 SDL2_VERSION=2.0.14
-CMAKE_VERSION=3.19.6
+CMAKE_VERSION=3.20.0
 CUDA_VERSION=11.0.2-1
diff --git a/build/raspberry-pi-os_armv6/Dockerfile b/build/raspberry-pi-os_armv6/Dockerfile
index 4feb2e44..e92b2425 100644
--- a/build/raspberry-pi-os_armv6/Dockerfile
+++ b/build/raspberry-pi-os_armv6/Dockerfile
@@ -78,5 +78,5 @@ RUN git clone --branch v$CLI11_VERSION --depth 1 https://github.com/CLIUtils/CLI
 # CMake のインストール
 ARG CMAKE_VERSION
 COPY script/get_cmake.sh /root/
-RUN /root/get_cmake.sh "$CMAKE_VERSION" Linux /root
+RUN /root/get_cmake.sh "$CMAKE_VERSION" linux /root
 ENV PATH "/root/cmake/bin:$PATH"
diff --git a/build/raspberry-pi-os_armv7/Dockerfile b/build/raspberry-pi-os_armv7/Dockerfile
index f9cb3071..3acabb84 100644
--- a/build/raspberry-pi-os_armv7/Dockerfile
+++ b/build/raspberry-pi-os_armv7/Dockerfile
@@ -78,7 +78,7 @@ RUN git clone --branch v$CLI11_VERSION --depth 1 https://github.com/CLIUtils/CLI
 # CMake のインストール
 ARG CMAKE_VERSION
 COPY script/get_cmake.sh /root/
-RUN /root/get_cmake.sh "$CMAKE_VERSION" Linux /root
+RUN /root/get_cmake.sh "$CMAKE_VERSION" linux /root
 ENV PATH "/root/cmake/bin:$PATH"
 
 # SDL2 のビルド
diff --git a/build/raspberry-pi-os_armv8/Dockerfile b/build/raspberry-pi-os_armv8/Dockerfile
index 6e7c3c83..eea70952 100644
--- a/build/raspberry-pi-os_armv8/Dockerfile
+++ b/build/raspberry-pi-os_armv8/Dockerfile
@@ -78,5 +78,5 @@ RUN git clone --branch v$CLI11_VERSION --depth 1 https://github.com/CLIUtils/CLI
 # CMake のインストール
 ARG CMAKE_VERSION
 COPY script/get_cmake.sh /root/
-RUN /root/get_cmake.sh "$CMAKE_VERSION" Linux /root
+RUN /root/get_cmake.sh "$CMAKE_VERSION" linux /root
 ENV PATH "/root/cmake/bin:$PATH"
diff --git a/build/ubuntu-18.04_armv8_jetson_nano/Dockerfile b/build/ubuntu-18.04_armv8_jetson_nano/Dockerfile
index 2c6c6a22..536147af 100644
--- a/build/ubuntu-18.04_armv8_jetson_nano/Dockerfile
+++ b/build/ubuntu-18.04_armv8_jetson_nano/Dockerfile
@@ -83,7 +83,7 @@ RUN git clone --branch v$CLI11_VERSION --depth 1 https://github.com/CLIUtils/CLI
 # CMake のインストール
 ARG CMAKE_VERSION
 COPY script/get_cmake.sh /root/
-RUN /root/get_cmake.sh "$CMAKE_VERSION" Linux /root
+RUN /root/get_cmake.sh "$CMAKE_VERSION" linux /root
 ENV PATH "/root/cmake/bin:$PATH"
 
 # SDL2 のビルド
diff --git a/build/ubuntu-18.04_armv8_jetson_xavier/Dockerfile b/build/ubuntu-18.04_armv8_jetson_xavier/Dockerfile
index 2c6c6a22..536147af 100644
--- a/build/ubuntu-18.04_armv8_jetson_xavier/Dockerfile
+++ b/build/ubuntu-18.04_armv8_jetson_xavier/Dockerfile
@@ -83,7 +83,7 @@ RUN git clone --branch v$CLI11_VERSION --depth 1 https://github.com/CLIUtils/CLI
 # CMake のインストール
 ARG CMAKE_VERSION
 COPY script/get_cmake.sh /root/
-RUN /root/get_cmake.sh "$CMAKE_VERSION" Linux /root
+RUN /root/get_cmake.sh "$CMAKE_VERSION" linux /root
 ENV PATH "/root/cmake/bin:$PATH"
 
 # SDL2 のビルド
diff --git a/build/ubuntu-18.04_x86_64/Dockerfile b/build/ubuntu-18.04_x86_64/Dockerfile
index e170fa48..f14811b3 100644
--- a/build/ubuntu-18.04_x86_64/Dockerfile
+++ b/build/ubuntu-18.04_x86_64/Dockerfile
@@ -66,7 +66,7 @@ RUN git clone --branch v$CLI11_VERSION --depth 1 https://github.com/CLIUtils/CLI
 # CMake のインストール
 ARG CMAKE_VERSION
 COPY script/get_cmake.sh /root/
-RUN /root/get_cmake.sh "$CMAKE_VERSION" Linux /root
+RUN /root/get_cmake.sh "$CMAKE_VERSION" linux /root
 ENV PATH "/root/cmake/bin:$PATH"
 
 # SDL2 のビルド
diff --git a/build/ubuntu-20.04_x86_64/Dockerfile b/build/ubuntu-20.04_x86_64/Dockerfile
index 7ceaf0db..dbaba38d 100644
--- a/build/ubuntu-20.04_x86_64/Dockerfile
+++ b/build/ubuntu-20.04_x86_64/Dockerfile
@@ -66,7 +66,7 @@ RUN git clone --branch v$CLI11_VERSION --depth 1 https://github.com/CLIUtils/CLI
 # CMake のインストール
 ARG CMAKE_VERSION
 COPY script/get_cmake.sh /root/
-RUN /root/get_cmake.sh "$CMAKE_VERSION" Linux /root
+RUN /root/get_cmake.sh "$CMAKE_VERSION" linux /root
 ENV PATH "/root/cmake/bin:$PATH"
 
 # SDL2 のビルド
diff --git a/src/hwenc_jetson/jetson_video_encoder.cpp b/src/hwenc_jetson/jetson_video_encoder.cpp
index 087f1666..8b6b69a5 100644
--- a/src/hwenc_jetson/jetson_video_encoder.cpp
+++ b/src/hwenc_jetson/jetson_video_encoder.cpp
@@ -902,6 +902,13 @@ int32_t JetsonVideoEncoder::SendFrame(unsigned char* buffer,
                                       size_t size,
                                       std::unique_ptr<FrameParams> params,
                                       v4l2_ctrl_videoenc_outputbuf_metadata enc_metadata) {
+  if (!callback_) {
+    RTC_LOG(LS_WARNING)
+        << "InitEncode() has been called, but a callback function "
+        << "has not been set with RegisterEncodeCompleteCallback()";
+    return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
+  }
+
   encoded_image_.SetTimestamp(params->timestamp_rtp);
   encoded_image_.SetColorSpace(params->color_space);
   encoded_image_._encodedWidth = params->width;