diff --git a/Dockerfile b/Dockerfile
index c726351..8dd1ca5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,38 +1,13 @@
-FROM ubuntu:18.04
+FROM ubuntu:20.04
 
-RUN apt-get update -qq && apt-get install -qqy --no-install-recommends \
+RUN apt-get update -qq && \
+    DEBIAN_FRONTEND="noninteractive" apt-get install -qqy --no-install-recommends \
     git wget bzip2 file unzip libtool pkg-config cmake build-essential \
     automake yasm gettext autopoint vim-tiny python3 python3-distutils \
     ninja-build ca-certificates curl less zip && \
     apt-get clean -y && \
     rm -rf /var/lib/apt/lists/*
 
-# Manually install a newer version of CMake; this is needed since building
-# LLVM requires CMake 3.13.4, while Ubuntu 18.04 ships with 3.10.2. If
-# updating to a newer distribution, this can be dropped.
-RUN cd /opt && \
-    curl -LO https://github.com/Kitware/CMake/releases/download/v3.20.1/cmake-3.20.1-Linux-$(uname -m).tar.gz && \
-    tar -zxf cmake-*.tar.gz && \
-    rm cmake-*.tar.gz && \
-    mv cmake-* cmake
-ENV PATH=/opt/cmake/bin:$PATH
-
-# Install a newer version of Git; the version of Git in Ubuntu 18.04 is
-# said to have issues with submodules, see e.g.
-# https://github.com/mstorsjo/llvm-mingw/pull/210#issuecomment-870104971 and
-# https://github.com/mstorsjo/llvm-mingw/pull/210#issuecomment-873486503.
-# This isn't needed for building LLVM itself, but makes the built Docker
-# image more useful for use as image for building other projects. If updating
-# to a newer distribution, this can be dropped.
-RUN apt-get update -qq && \
-    apt-get install -qqy --no-install-recommends software-properties-common && \
-    add-apt-repository ppa:git-core/ppa && \
-    apt-get update -qq && \
-    apt-get upgrade -qqy git && \
-    apt-get clean -y && \
-    rm -rf /var/lib/apt/lists/*
-
-
 RUN git config --global user.name "LLVM MinGW" && \
     git config --global user.email root@localhost
 
diff --git a/Dockerfile.dev b/Dockerfile.dev
index 2046a73..4db9eb3 100644
--- a/Dockerfile.dev
+++ b/Dockerfile.dev
@@ -1,38 +1,13 @@
-FROM ubuntu:18.04
+FROM ubuntu:20.04
 
-RUN apt-get update -qq && apt-get install -qqy --no-install-recommends \
+RUN apt-get update -qq && \
+    DEBIAN_FRONTEND="noninteractive" apt-get install -qqy --no-install-recommends \
     git wget bzip2 file unzip libtool pkg-config cmake build-essential \
     automake yasm gettext autopoint vim-tiny python3 python3-distutils \
     ninja-build ca-certificates curl less zip && \
     apt-get clean -y && \
     rm -rf /var/lib/apt/lists/*
 
-# Manually install a newer version of CMake; this is needed since building
-# LLVM requires CMake 3.13.4, while Ubuntu 18.04 ships with 3.10.2. If
-# updating to a newer distribution, this can be dropped.
-RUN cd /opt && \
-    curl -LO https://github.com/Kitware/CMake/releases/download/v3.20.1/cmake-3.20.1-Linux-$(uname -m).tar.gz && \
-    tar -zxf cmake-*.tar.gz && \
-    rm cmake-*.tar.gz && \
-    mv cmake-* cmake
-ENV PATH=/opt/cmake/bin:$PATH
-
-# Install a newer version of Git; the version of Git in Ubuntu 18.04 is
-# said to have issues with submodules, see e.g.
-# https://github.com/mstorsjo/llvm-mingw/pull/210#issuecomment-870104971 and
-# https://github.com/mstorsjo/llvm-mingw/pull/210#issuecomment-873486503.
-# This isn't needed for building LLVM itself, but makes the built Docker
-# image more useful for use as image for building other projects. If updating
-# to a newer distribution, this can be dropped.
-RUN apt-get update -qq && \
-    apt-get install -qqy --no-install-recommends software-properties-common && \
-    add-apt-repository ppa:git-core/ppa && \
-    apt-get update -qq && \
-    apt-get upgrade -qqy git && \
-    apt-get clean -y && \
-    rm -rf /var/lib/apt/lists/*
-
-
 RUN git config --global user.name "LLVM MinGW" && \
     git config --global user.email root@localhost
 
diff --git a/release.sh b/release.sh
index b4fd1ff..40bdc72 100755
--- a/release.sh
+++ b/release.sh
@@ -29,7 +29,7 @@ fi
 
 time docker build -f Dockerfile . -t mstorsjo/llvm-mingw:latest -t mstorsjo/llvm-mingw:$TAG
 
-DISTRO=ubuntu-18.04-$(uname -m)
+DISTRO=ubuntu-20.04-$(uname -m)
 docker run --rm mstorsjo/llvm-mingw:latest sh -c "cd /opt && mv llvm-mingw llvm-mingw-$TAG-ucrt-$DISTRO && tar -Jcvf - llvm-mingw-$TAG-ucrt-$DISTRO" > llvm-mingw-$TAG-ucrt-$DISTRO.tar.xz
 
 if [ -n "$NATIVEONLY" ]; then