diff --git a/Dockerfile b/Dockerfile
index 38fd2dd..4ebbcaf 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,7 +24,7 @@
 # Or simply recreate the directory from the host with:
 # rm -rf ~/.buildozer && mkdir ~/.buildozer
 
-FROM ubuntu:18.04
+FROM ubuntu:20.04
 
 ENV USER="user"
 ENV HOME_DIR="/home/${USER}"
@@ -33,8 +33,8 @@ ENV WORK_DIR="${HOME_DIR}/hostcwd" \
     PATH="${HOME_DIR}/.local/bin:${PATH}"
 
 # configures locale
-RUN apt update -qq > /dev/null && \
-    apt install -qq --yes --no-install-recommends \
+RUN apt update -qq > /dev/null \
+    && DEBIAN_FRONTEND=noninteractive apt install -qq --yes --no-install-recommends \
     locales && \
     locale-gen en_US.UTF-8
 ENV LANG="en_US.UTF-8" \
@@ -42,8 +42,8 @@ ENV LANG="en_US.UTF-8" \
     LC_ALL="en_US.UTF-8"
 
 # system requirements to build most of the recipes
-RUN apt update -qq > /dev/null && \
-    apt install -qq --yes --no-install-recommends \
+RUN apt update -qq > /dev/null \
+    && DEBIAN_FRONTEND=noninteractive apt install -qq --yes --no-install-recommends \
     autoconf \
     automake \
     build-essential \
@@ -55,7 +55,7 @@ RUN apt update -qq > /dev/null && \
     libltdl-dev \
     libssl-dev \
     libtool \
-    openjdk-8-jdk \
+    openjdk-13-jdk \
     patch \
     pkg-config \
     python3-pip \
diff --git a/docs/source/installation.rst b/docs/source/installation.rst
index 5816b0f..d7d790b 100644
--- a/docs/source/installation.rst
+++ b/docs/source/installation.rst
@@ -21,7 +21,7 @@ Android on Ubuntu 20.04 (64bit)
 ::
 
     sudo apt update
-    sudo apt install -y git zip unzip openjdk-8-jdk python3-pip autoconf libtool pkg-config zlib1g-dev libncurses5-dev libncursesw5-dev libtinfo5 cmake libffi-dev libssl-dev
+    sudo apt install -y git zip unzip openjdk-13-jdk python3-pip autoconf libtool pkg-config zlib1g-dev libncurses5-dev libncursesw5-dev libtinfo5 cmake libffi-dev libssl-dev
     pip3 install --user --upgrade Cython==0.29.19 virtualenv  # the --user should be removed if you do this in a venv
 
     # add the following line at the end of your ~/.bashrc file