diff --git a/docker/torch1.12.1-cuda11.3.dockerfile b/docker/torch1.12.1-cuda11.3.dockerfile
index b6273682f..b359ea72c 100644
--- a/docker/torch1.12.1-cuda11.3.dockerfile
+++ b/docker/torch1.12.1-cuda11.3.dockerfile
@@ -1,5 +1,7 @@
 FROM pytorch/pytorch:1.12.1-cuda11.3-cudnn8-runtime
 
+ENV LC_ALL C.UTF-8
+
 ARG K2_VERSION="1.24.3.dev20230725+cuda11.3.torch1.12.1"
 ARG KALDIFEAT_VERSION="1.25.0.dev20230726+cuda11.3.torch1.12.1"
 ARG TORCHAUDIO_VERSION="0.12.1+cu113"
@@ -55,8 +57,6 @@ RUN git clone https://github.com/k2-fsa/icefall /workspace/icefall && \
 
 ENV PYTHONPATH /workspace/icefall:$PYTHONPATH
 
-ENV LD_LIBRARY_PATH /opt/conda/lib/stubs:$LD_LIBRARY_PATH
-
 WORKDIR /workspace/icefall
 
 
diff --git a/docker/torch1.13.0-cuda11.6.dockerfile b/docker/torch1.13.0-cuda11.6.dockerfile
index 69dbe652f..71daff723 100644
--- a/docker/torch1.13.0-cuda11.6.dockerfile
+++ b/docker/torch1.13.0-cuda11.6.dockerfile
@@ -1,5 +1,7 @@
 FROM pytorch/pytorch:1.13.0-cuda11.6-cudnn8-runtime
 
+ENV LC_ALL C.UTF-8
+
 ARG K2_VERSION="1.24.3.dev20230725+cuda11.6.torch1.13.0"
 ARG KALDIFEAT_VERSION="1.25.0.dev20230726+cuda11.6.torch1.13.0"
 ARG TORCHAUDIO_VERSION="0.13.0+cu116"
diff --git a/docker/torch1.9.0-cuda10.2.dockerfile b/docker/torch1.9.0-cuda10.2.dockerfile
index c50836545..4d52f7ad6 100644
--- a/docker/torch1.9.0-cuda10.2.dockerfile
+++ b/docker/torch1.9.0-cuda10.2.dockerfile
@@ -1,5 +1,7 @@
 FROM pytorch/pytorch:1.9.0-cuda10.2-cudnn7-runtime
 
+ENV LC_ALL C.UTF-8
+
 ARG K2_VERSION="1.24.3.dev20230726+cuda10.2.torch1.9.0"
 ARG KALDIFEAT_VERSION="1.25.0.dev20230726+cuda10.2.torch1.9.0"
 ARG TORCHAUDIO_VERSION="0.9.0"
@@ -55,8 +57,6 @@ RUN git clone https://github.com/k2-fsa/icefall /workspace/icefall && \
 
 ENV PYTHONPATH /workspace/icefall:$PYTHONPATH
 
-ENV LD_LIBRARY_PATH /opt/conda/lib/stubs:$LD_LIBRARY_PATH
-
 WORKDIR /workspace/icefall
 
 
diff --git a/docker/torch2.0.0-cuda11.7.dockerfile b/docker/torch2.0.0-cuda11.7.dockerfile
index 410bd5a1a..a0b0be45b 100644
--- a/docker/torch2.0.0-cuda11.7.dockerfile
+++ b/docker/torch2.0.0-cuda11.7.dockerfile
@@ -1,5 +1,7 @@
 FROM pytorch/pytorch:2.0.0-cuda11.7-cudnn8-runtime
 
+ENV LC_ALL C.UTF-8
+
 ARG K2_VERSION="1.24.3.dev20230718+cuda11.7.torch2.0.0"
 ARG KALDIFEAT_VERSION="1.25.0.dev20230726+cuda11.7.torch2.0.0"
 ARG TORCHAUDIO_VERSION="2.0.0+cu117"
@@ -55,8 +57,6 @@ RUN git clone https://github.com/k2-fsa/icefall /workspace/icefall && \
 
 ENV PYTHONPATH /workspace/icefall:$PYTHONPATH
 
-ENV LD_LIBRARY_PATH /opt/conda/lib/stubs:$LD_LIBRARY_PATH
-
 WORKDIR /workspace/icefall
 
 
diff --git a/docker/torch2.0.1-cuda11.7.dockerfile b/docker/torch2.0.1-cuda11.7.dockerfile
index b69da28c7..acfe2c9e5 100644
--- a/docker/torch2.0.1-cuda11.7.dockerfile
+++ b/docker/torch2.0.1-cuda11.7.dockerfile
@@ -1,5 +1,7 @@
 FROM pytorch/pytorch:2.0.1-cuda11.7-cudnn8-runtime
 
+ENV LC_ALL C.UTF-8
+
 ARG K2_VERSION="1.24.3.dev20230718+cuda11.7.torch2.0.1"
 ARG KALDIFEAT_VERSION="1.25.0.dev20230726+cuda11.7.torch2.0.1"
 ARG TORCHAUDIO_VERSION="2.0.1+cu117"
@@ -53,10 +55,6 @@ RUN git clone https://github.com/k2-fsa/icefall /workspace/icefall && \
 	cd /workspace/icefall && \
 	pip install --no-cache-dir -r requirements.txt
 
-ENV PYTHONPATH /workspace/icefall:$PYTHONPATH
-
-ENV LD_LIBRARY_PATH /opt/conda/lib/stubs:$LD_LIBRARY_PATH
-
 WORKDIR /workspace/icefall