diff --git a/Dockerfile b/Dockerfile
index c2c0be2..e2dc96e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,7 +24,8 @@ USER root
 
 # install cuda toolkit 
 # https://developer.nvidia.com/cuda-11.1.0-download-archive?target_os=Linux&target_arch=x86_64&target_distro=Ubuntu&target_version=2004&target_type=debnetwork
-RUN wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-ubuntu2004.pin && \
+RUN apt-get install -y software-properties-common && \
+    wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-ubuntu2004.pin && \
     mv cuda-ubuntu2004.pin /etc/apt/preferences.d/cuda-repository-pin-600  && \
     apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/7fa2af80.pub  && \
     add-apt-repository "deb https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/ /"  && \