diff --git a/.travis.yml b/.travis.yml
index 115efab95..60d7bdae1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,9 @@ language: bash
 services: docker
 
 env:
+  - VERSION=2.6-rc VARIANT=stretch
+  - VERSION=2.6-rc VARIANT=stretch/slim
+  - VERSION=2.6-rc VARIANT=alpine3.7
   - VERSION=2.5 VARIANT=stretch
   - VERSION=2.5 VARIANT=stretch/slim
   - VERSION=2.5 VARIANT=alpine3.7
diff --git a/2.6-rc/alpine3.7/Dockerfile b/2.6-rc/alpine3.7/Dockerfile
new file mode 100644
index 000000000..dc65fd9e7
--- /dev/null
+++ b/2.6-rc/alpine3.7/Dockerfile
@@ -0,0 +1,111 @@
+FROM alpine:3.7
+
+# skip installing gem documentation
+RUN mkdir -p /usr/local/etc \
+	&& { \
+		echo 'install: --no-document'; \
+		echo 'update: --no-document'; \
+	} >> /usr/local/etc/gemrc
+
+ENV RUBY_MAJOR 2.6-rc
+ENV RUBY_VERSION 2.6.0-preview1
+ENV RUBY_DOWNLOAD_SHA256 1d99139116e4e245ce543edb137b2a8873c26e9f0bde88d8cee6789617cc8d0e
+ENV RUBYGEMS_VERSION 2.7.6
+ENV BUNDLER_VERSION 1.16.1
+
+# some of ruby's build scripts are written in ruby
+#   we purge system ruby later to make sure our final image uses what we just built
+# readline-dev vs libedit-dev: https://bugs.ruby-lang.org/issues/11869 and https://github.com/docker-library/ruby/issues/75
+RUN set -ex \
+	\
+	&& apk add --no-cache --virtual .ruby-builddeps \
+		autoconf \
+		bison \
+		bzip2 \
+		bzip2-dev \
+		ca-certificates \
+		coreutils \
+		dpkg-dev dpkg \
+		gcc \
+		gdbm-dev \
+		glib-dev \
+		libc-dev \
+		libffi-dev \
+		libressl \
+		libressl-dev \
+		libxml2-dev \
+		libxslt-dev \
+		linux-headers \
+		make \
+		ncurses-dev \
+		procps \
+		readline-dev \
+		ruby \
+		tar \
+		xz \
+		yaml-dev \
+		zlib-dev \
+	\
+	&& wget -O ruby.tar.xz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR%-rc}/ruby-$RUBY_VERSION.tar.xz" \
+	&& echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.xz" | sha256sum -c - \
+	\
+	&& mkdir -p /usr/src/ruby \
+	&& tar -xJf ruby.tar.xz -C /usr/src/ruby --strip-components=1 \
+	&& rm ruby.tar.xz \
+	\
+	&& cd /usr/src/ruby \
+	\
+# hack in "ENABLE_PATH_CHECK" disabling to suppress:
+#   warning: Insecure world writable dir
+	&& { \
+		echo '#define ENABLE_PATH_CHECK 0'; \
+		echo; \
+		cat file.c; \
+	} > file.c.new \
+	&& mv file.c.new file.c \
+	\
+	&& autoconf \
+	&& gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
+# the configure script does not detect isnan/isinf as macros
+	&& export ac_cv_func_isnan=yes ac_cv_func_isinf=yes \
+	&& ./configure \
+		--build="$gnuArch" \
+		--disable-install-doc \
+		--enable-shared \
+	&& make -j "$(nproc)" \
+	&& make install \
+	\
+	&& runDeps="$( \
+		scanelf --needed --nobanner --format '%n#p' --recursive /usr/local \
+			| tr ',' '\n' \
+			| sort -u \
+			| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
+	)" \
+	&& apk add --virtual .ruby-rundeps $runDeps \
+		bzip2 \
+		ca-certificates \
+		libffi-dev \
+		libressl-dev \
+		procps \
+		yaml-dev \
+		zlib-dev \
+	&& apk del .ruby-builddeps \
+	&& cd / \
+	&& rm -r /usr/src/ruby \
+	\
+	&& gem update --system "$RUBYGEMS_VERSION" \
+	&& gem install bundler --version "$BUNDLER_VERSION" --force \
+	&& rm -r /root/.gem/
+
+# install things globally, for great justice
+# and don't create ".bundle" in all our apps
+ENV GEM_HOME /usr/local/bundle
+ENV BUNDLE_PATH="$GEM_HOME" \
+	BUNDLE_BIN="$GEM_HOME/bin" \
+	BUNDLE_SILENCE_ROOT_WARNING=1 \
+	BUNDLE_APP_CONFIG="$GEM_HOME"
+ENV PATH $BUNDLE_BIN:$PATH
+RUN mkdir -p "$GEM_HOME" "$BUNDLE_BIN" \
+	&& chmod 777 "$GEM_HOME" "$BUNDLE_BIN"
+
+CMD [ "irb" ]
diff --git a/2.6-rc/stretch/Dockerfile b/2.6-rc/stretch/Dockerfile
new file mode 100644
index 000000000..97cb7c25f
--- /dev/null
+++ b/2.6-rc/stretch/Dockerfile
@@ -0,0 +1,76 @@
+FROM buildpack-deps:stretch
+
+# skip installing gem documentation
+RUN mkdir -p /usr/local/etc \
+	&& { \
+		echo 'install: --no-document'; \
+		echo 'update: --no-document'; \
+	} >> /usr/local/etc/gemrc
+
+ENV RUBY_MAJOR 2.6-rc
+ENV RUBY_VERSION 2.6.0-preview1
+ENV RUBY_DOWNLOAD_SHA256 1d99139116e4e245ce543edb137b2a8873c26e9f0bde88d8cee6789617cc8d0e
+ENV RUBYGEMS_VERSION 2.7.6
+ENV BUNDLER_VERSION 1.16.1
+
+# some of ruby's build scripts are written in ruby
+#   we purge system ruby later to make sure our final image uses what we just built
+RUN set -ex \
+	\
+	&& buildDeps=' \
+		bison \
+		dpkg-dev \
+		libgdbm-dev \
+		ruby \
+	' \
+	&& apt-get update \
+	&& apt-get install -y --no-install-recommends $buildDeps \
+	&& rm -rf /var/lib/apt/lists/* \
+	\
+	&& wget -O ruby.tar.xz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR%-rc}/ruby-$RUBY_VERSION.tar.xz" \
+	&& echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.xz" | sha256sum -c - \
+	\
+	&& mkdir -p /usr/src/ruby \
+	&& tar -xJf ruby.tar.xz -C /usr/src/ruby --strip-components=1 \
+	&& rm ruby.tar.xz \
+	\
+	&& cd /usr/src/ruby \
+	\
+# hack in "ENABLE_PATH_CHECK" disabling to suppress:
+#   warning: Insecure world writable dir
+	&& { \
+		echo '#define ENABLE_PATH_CHECK 0'; \
+		echo; \
+		cat file.c; \
+	} > file.c.new \
+	&& mv file.c.new file.c \
+	\
+	&& autoconf \
+	&& gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
+	&& ./configure \
+		--build="$gnuArch" \
+		--disable-install-doc \
+		--enable-shared \
+	&& make -j "$(nproc)" \
+	&& make install \
+	\
+	&& apt-get purge -y --auto-remove $buildDeps \
+	&& cd / \
+	&& rm -r /usr/src/ruby \
+	\
+	&& gem update --system "$RUBYGEMS_VERSION" \
+	&& gem install bundler --version "$BUNDLER_VERSION" --force \
+	&& rm -r /root/.gem/
+
+# install things globally, for great justice
+# and don't create ".bundle" in all our apps
+ENV GEM_HOME /usr/local/bundle
+ENV BUNDLE_PATH="$GEM_HOME" \
+	BUNDLE_BIN="$GEM_HOME/bin" \
+	BUNDLE_SILENCE_ROOT_WARNING=1 \
+	BUNDLE_APP_CONFIG="$GEM_HOME"
+ENV PATH $BUNDLE_BIN:$PATH
+RUN mkdir -p "$GEM_HOME" "$BUNDLE_BIN" \
+	&& chmod 777 "$GEM_HOME" "$BUNDLE_BIN"
+
+CMD [ "irb" ]
diff --git a/2.6-rc/stretch/slim/Dockerfile b/2.6-rc/stretch/slim/Dockerfile
new file mode 100644
index 000000000..590e5eabb
--- /dev/null
+++ b/2.6-rc/stretch/slim/Dockerfile
@@ -0,0 +1,102 @@
+FROM debian:stretch
+
+RUN apt-get update \
+	&& apt-get install -y --no-install-recommends \
+		bzip2 \
+		ca-certificates \
+		libffi-dev \
+		libgdbm3 \
+		libssl-dev \
+		libyaml-dev \
+		procps \
+		zlib1g-dev \
+	&& rm -rf /var/lib/apt/lists/*
+
+# skip installing gem documentation
+RUN mkdir -p /usr/local/etc \
+	&& { \
+		echo 'install: --no-document'; \
+		echo 'update: --no-document'; \
+	} >> /usr/local/etc/gemrc
+
+ENV RUBY_MAJOR 2.6-rc
+ENV RUBY_VERSION 2.6.0-preview1
+ENV RUBY_DOWNLOAD_SHA256 1d99139116e4e245ce543edb137b2a8873c26e9f0bde88d8cee6789617cc8d0e
+ENV RUBYGEMS_VERSION 2.7.6
+ENV BUNDLER_VERSION 1.16.1
+
+# some of ruby's build scripts are written in ruby
+#   we purge system ruby later to make sure our final image uses what we just built
+RUN set -ex \
+	\
+	&& buildDeps=' \
+		autoconf \
+		bison \
+		dpkg-dev \
+		gcc \
+		libbz2-dev \
+		libgdbm-dev \
+		libglib2.0-dev \
+		libncurses-dev \
+		libreadline-dev \
+		libxml2-dev \
+		libxslt-dev \
+		make \
+		ruby \
+		wget \
+		xz-utils \
+	' \
+	&& apt-get update \
+	&& apt-get install -y --no-install-recommends $buildDeps \
+	&& rm -rf /var/lib/apt/lists/* \
+	\
+	&& wget -O ruby.tar.xz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR%-rc}/ruby-$RUBY_VERSION.tar.xz" \
+	&& echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.xz" | sha256sum -c - \
+	\
+	&& mkdir -p /usr/src/ruby \
+	&& tar -xJf ruby.tar.xz -C /usr/src/ruby --strip-components=1 \
+	&& rm ruby.tar.xz \
+	\
+	&& cd /usr/src/ruby \
+	\
+# hack in "ENABLE_PATH_CHECK" disabling to suppress:
+#   warning: Insecure world writable dir
+	&& { \
+		echo '#define ENABLE_PATH_CHECK 0'; \
+		echo; \
+		cat file.c; \
+	} > file.c.new \
+	&& mv file.c.new file.c \
+	\
+	&& autoconf \
+	&& gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
+	&& ./configure \
+		--build="$gnuArch" \
+		--disable-install-doc \
+		--enable-shared \
+	&& make -j "$(nproc)" \
+	&& make install \
+	\
+	&& dpkg-query --show --showformat '${package}\n' \
+		| grep -P '^libreadline\d+$' \
+		| xargs apt-mark manual \
+	&& apt-get purge -y --auto-remove $buildDeps \
+	&& cd / \
+	&& rm -r /usr/src/ruby \
+	\
+	&& gem update --system "$RUBYGEMS_VERSION" \
+	&& gem install bundler --version "$BUNDLER_VERSION" --force \
+	&& rm -r /root/.gem/
+
+# install things globally, for great justice
+# and don't create ".bundle" in all our apps
+ENV GEM_HOME /usr/local/bundle
+ENV BUNDLE_PATH="$GEM_HOME" \
+	BUNDLE_BIN="$GEM_HOME/bin" \
+	BUNDLE_SILENCE_ROOT_WARNING=1 \
+	BUNDLE_APP_CONFIG="$GEM_HOME"
+ENV PATH $BUNDLE_BIN:$PATH
+RUN mkdir -p "$GEM_HOME" "$BUNDLE_BIN" \
+	&& chmod 777 "$GEM_HOME" "$BUNDLE_BIN"
+
+CMD [ "irb" ]