diff --git a/build/docker/ubuntu-xenial/Dockerfile b/build/docker/ubuntu-xenial/Dockerfile
index 5033d77..1428fac 100644
--- a/build/docker/ubuntu-xenial/Dockerfile
+++ b/build/docker/ubuntu-xenial/Dockerfile
@@ -74,6 +74,8 @@
 
 ### languages
 
+# TODO: "apt-get install" without "apt-get update" in the same "RUN" step can cause cache issues if modified later.
+# See https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#run
 RUN apt-get install -y --no-install-recommends \
 `# C++ dependencies` \
       libboost-dev \
@@ -118,13 +120,16 @@
       aspnetcore-runtime-6.0 \
       dotnet-apphost-pack-6.0
 
-RUN apt-get install -y --no-install-recommends \
-`# Erlang dependencies` \
-      erlang-base \
-      erlang-eunit \
-      erlang-dev \
-      erlang-tools \
-      rebar
+# Erlang dependencies
+ARG ERLANG_OTP_VERSION=18.3.4.11
+ARG ERLANG_REBAR_VERSION=3.13.2
+RUN apt-get update && apt-get install -y --no-install-recommends automake libncurses5-dev && \
+    curl https://raw.githubusercontent.com/kerl/kerl/master/kerl -o /usr/local/bin/kerl && chmod +x /usr/local/bin/kerl && \
+    kerl build $ERLANG_OTP_VERSION && kerl install $ERLANG_OTP_VERSION /usr/local/lib/otp/ && . /usr/local/lib/otp/activate && \
+    curl https://s3.amazonaws.com/rebar3/rebar3 -o /usr/local/bin/rebar3 && chmod +x /usr/local/bin/rebar3 && \
+    curl -ssLo /usr/local/bin/rebar3 https://github.com/erlang/rebar3/releases/download/${ERLANG_REBAR_VERSION}/rebar3 && chmod +x /usr/local/bin/rebar3 && \
+    rebar3 --version
+ENV PATH /usr/local/lib/otp/bin:$PATH
 
 RUN apt-get install -y --no-install-recommends \
 `# GlibC dependencies` \
@@ -246,11 +251,12 @@
     locale-gen de_DE.UTF-8 && \
     update-locale
 
-# Clean up
-RUN rm -rf /var/cache/apt/* && \
-    rm -rf /var/lib/apt/lists/* && \
-    rm -rf /tmp/* && \
-    rm -rf /var/tmp/*
+# NOTE: this does not reduce the image size but adds an additional layer.
+# # Clean up
+# RUN rm -rf /var/cache/apt/* && \
+#     rm -rf /var/lib/apt/lists/* && \
+#     rm -rf /tmp/* && \
+#     rm -rf /var/tmp/*
 
 ENV DOTNET_CLI_TELEMETRY_OPTOUT 1
 ENV THRIFT_ROOT /thrift