diff --git a/build/x86_64_debian/Dockerfile b/build/x86_64_debian/Dockerfile
index 31a04a90..f6aacdae 100644
--- a/build/x86_64_debian/Dockerfile
+++ b/build/x86_64_debian/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:9
+FROM debian:10
 
 RUN apt-get -y update \
  && apt-get -y install \
@@ -19,6 +19,8 @@ RUN apt-get -y update \
  # RVM GPG keys.
  && mkdir -p ~/.gnupg && echo "disable-ipv6" >> ~/.gnupg/dirmngr.conf \
  && gpg2 --keyserver hkp://keyserver.ubuntu.com --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB \
+ # Workaround for https://stackoverflow.com/q/64653051.
+ && ln -s /bin/mkdir /usr/bin/mkdir \
  # Install RVM.
  && curl -sSL -o get-rvm-io.sh https://get.rvm.io \
  && (echo "7bbf79be95e516f72945e558a4290b40ff8714158140a00991d42172ff78e209  get-rvm-io.sh" | sha256sum --check) \