diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e151a2717..00c6e8d9b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -294,7 +294,7 @@ jobs:
   build-push-image:
     runs-on: ubuntu-latest
     needs: [config]
-    if: github.event_name == 'schedule'
+    if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
     strategy:
       fail-fast: false
       matrix:
@@ -307,7 +307,6 @@ jobs:
             file: cryptol-remote-api/Dockerfile
             image: ghcr.io/galoisinc/cryptol-remote-api
             cache: ghcr.io/galoisinc/cache-cryptol-remote-api
-            if: ${{ github.event_name == 'schedule' }}
           - build-args: PORTABILITY=false
             file: cryptol-remote-api/Dockerfile
             image: ghcr.io/galoisinc/cryptol-remote-api
diff --git a/Dockerfile b/Dockerfile
index 58739509a..b8afbb1a8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,62 +1,21 @@
-FROM debian:buster-20210511 AS solvers
-
-# Install needed packages for building
-RUN apt-get update \
-    && apt-get install -y curl cmake gcc g++ git libreadline-dev unzip
-RUN useradd -m user
-RUN install -d -o user -g user /solvers
-USER user
-WORKDIR /solvers
-RUN mkdir -p rootfs/usr/local/bin
-
-# Get Z3 4.8.8 from GitHub
-RUN curl -L https://github.com/Z3Prover/z3/releases/download/z3-4.8.8/z3-4.8.8-x64-ubuntu-16.04.zip --output z3.zip && \
-    unzip z3.zip && \
-    mv z3-*/bin/z3 rootfs/usr/local/bin
-
-# Build abc from GitHub. (Latest version.)
-RUN git clone https://github.com/berkeley-abc/abc.git && \
-    ( cd abc && make -j$(nproc) ) && \
-    cp abc/abc rootfs/usr/local/bin
-
-# Build Boolector release 3.2.1 from source
-RUN curl -L https://github.com/Boolector/boolector/archive/3.2.1.tar.gz | tar xz && \
-    ( cd boolector* && ./contrib/setup-lingeling.sh && ./contrib/setup-btor2tools.sh && ./configure.sh && cd build && make -j$(nproc) ) && \
-    cp boolector*/build/bin/boolector rootfs/usr/local/bin
-
-# Install Yices 2.6.2
-RUN curl -L https://yices.csl.sri.com/releases/2.6.2/yices-2.6.2-x86_64-pc-linux-gnu-static-gmp.tar.gz | tar xz && \
-    cp yices*/bin/yices-smt2 rootfs/usr/local/bin \
-    && cp yices*/bin/yices rootfs/usr/local/bin
-
-# Install CVC4 1.8
-# The latest CVC4 1.8 and the release version has a minor discrepency between it, causing sbv to fail
-# https://github.com/CVC4/CVC4/releases/download/1.8/cvc4-1.8-x86_64-linux-opt
-#RUN latest="$(curl -sSL 'http://cvc4.cs.stanford.edu/downloads/builds/x86_64-linux-opt/unstable/' | grep linux-opt | tail -n1 | sed -e 's/.*href="//' -e 's/\([^>]*\)">.*$/\1/')" && \
-RUN latest="cvc4-2021-03-13-x86_64-linux-opt" && \
-    curl --output rootfs/usr/local/bin/cvc4 -sSL "https://cvc4.cs.stanford.edu/downloads/builds/x86_64-linux-opt/unstable/$latest"
-
-# Install MathSAT 5.6.3 - Uncomment if you are in compliance with MathSAT's license.
-# RUN curl -L https://mathsat.fbk.eu/download.php?file=mathsat-5.6.3-linux-x86_64.tar.gz | tar xz
-# RUN cp mathsat-5.6.3-linux-x86_64/bin/mathsat rootfs/usr/local/bin
-
-# Set executable and run tests
-RUN chmod +x rootfs/usr/local/bin/*
-
 FROM haskell:8.8.4 AS build
 
-RUN apt-get update && apt-get install -y libncurses-dev
-COPY --from=solvers /solvers/rootfs /
+RUN apt-get update && apt-get install -y libncurses-dev unzip
 RUN useradd -m cryptol
 COPY --chown=cryptol:cryptol . /cryptol
 USER cryptol
 WORKDIR /cryptol
+RUN mkdir -p rootfs/usr/local/bin
+WORKDIR /cryptol/rootfs/usr/local/bin
+RUN curl -o solvers.zip -sL "https://github.com/GaloisInc/what4-solvers/releases/download/snapshot-20210917/ubuntu-18.04-bin.zip"
+RUN unzip solvers.zip && rm solvers.zip && chmod +x *
+WORKDIR /cryptol
 ENV PATH=/cryptol/rootfs/usr/local/bin:$PATH
+RUN z3 --version
 ARG CRYPTOLPATH="/cryptol/.cryptol"
 ENV LANG=C.UTF-8 \
     LC_ALL=C.UTF-8
 COPY cabal.GHC-8.8.4.config cabal.project.freeze
-RUN mkdir -p rootfs/usr/local/bin
 RUN cabal v2-update && \
     cabal v2-build -j cryptol:exe:cryptol && \
     cp $(cabal v2-exec which cryptol) rootfs/usr/local/bin && \
@@ -66,8 +25,8 @@ ENV PATH=/usr/local/bin:/cryptol/rootfs/usr/local/bin:$PATH
 RUN    ! $(cryptol -c ":s prover=yices" | tail -n +2 | grep -q .) \
     #    && ! $(cryptol -c ":s prover=mathsat" | tail -n +2 | grep -q .) \
     && ! $(cryptol -c ":s prover=cvc4" | tail -n +2 | grep -q .) \
-    # && ! $(cryptol -c ":s prover=abc" | tail -n +2 | grep -q .) \
-    && ! $(cryptol -c ":s prover=boolector" | tail -n +2 | grep -q .) \
+    && ! $(cryptol -c ":s prover=abc" | tail -n +2 | grep -q .) \
+    # && ! $(cryptol -c ":s prover=boolector" | tail -n +2 | grep -q .) \
     && ! $(cryptol -c ":s prover=z3" | tail -n +2 | grep -q .)
 RUN mkdir -p rootfs/"${CRYPTOLPATH}" \
     && cp -r lib/* rootfs/"${CRYPTOLPATH}"
@@ -80,7 +39,6 @@ RUN apt-get update \
     && apt-get clean && rm -rf /var/lib/apt/lists/*
 RUN useradd -m cryptol && chown -R cryptol:cryptol /home/cryptol
 COPY --from=build /cryptol/rootfs /
-COPY --from=solvers /solvers/rootfs /
 USER cryptol
 ENV LANG=C.UTF-8 \
     LC_ALL=C.UTF-8
diff --git a/cryptol-remote-api/Dockerfile b/cryptol-remote-api/Dockerfile
index 58acb2c4f..3fd27ce70 100644
--- a/cryptol-remote-api/Dockerfile
+++ b/cryptol-remote-api/Dockerfile
@@ -1,59 +1,14 @@
 ARG GHCVER="8.10.3"
 ARG GHCVER_BOOTSTRAP="8.10.2"
-FROM debian:buster-20210511 AS solvers
-
-# Install needed packages for building
-RUN apt-get update \
-    && apt-get install -y curl cmake gcc g++ git libreadline-dev unzip
-RUN useradd -m user
-RUN install -d -o user -g user /solvers
-USER user
-WORKDIR /solvers
-RUN mkdir -p rootfs/usr/local/bin
-
-# Get Z3 4.8.8 from GitHub
-RUN curl -L https://github.com/Z3Prover/z3/releases/download/z3-4.8.8/z3-4.8.8-x64-ubuntu-16.04.zip --output z3.zip && \
-    unzip z3.zip && \
-    mv z3-*/bin/z3 rootfs/usr/local/bin
-
-# Build abc from GitHub. (Latest version.)
-RUN git clone https://github.com/berkeley-abc/abc.git && \
-    ( cd abc && make -j$(nproc) ) && \
-    cp abc/abc rootfs/usr/local/bin
-
-# Build Boolector release 3.2.1 from source
-RUN curl -L https://github.com/Boolector/boolector/archive/3.2.1.tar.gz | tar xz && \
-    ( cd boolector* && ./contrib/setup-lingeling.sh && ./contrib/setup-btor2tools.sh && ./configure.sh && cd build && make -j$(nproc) ) && \
-    cp boolector*/build/bin/boolector rootfs/usr/local/bin
-
-# Install Yices 2.6.2
-RUN curl -L https://yices.csl.sri.com/releases/2.6.2/yices-2.6.2-x86_64-pc-linux-gnu-static-gmp.tar.gz | tar xz && \
-    cp yices*/bin/yices-smt2 rootfs/usr/local/bin \
-    && cp yices*/bin/yices rootfs/usr/local/bin
-
-# Install CVC4 1.8
-# The latest CVC4 1.8 and the release version has a minor discrepency between it, causing sbv to fail
-# https://github.com/CVC4/CVC4/releases/download/1.8/cvc4-1.8-x86_64-linux-opt
-RUN latest="$(curl -sSL 'http://cvc4.cs.stanford.edu/downloads/builds/x86_64-linux-opt/unstable/' | grep linux-opt | tail -n1 | sed -e 's/.*href="//' -e 's/\([^>]*\)">.*$/\1/')" && \
-    curl --output rootfs/usr/local/bin/cvc4 -sSL "https://cvc4.cs.stanford.edu/downloads/builds/x86_64-linux-opt/unstable/$latest"
-
-# Install MathSAT 5.6.3 - Uncomment if you are in compliance with MathSAT's license.
-# RUN curl -L https://mathsat.fbk.eu/download.php?file=mathsat-5.6.3-linux-x86_64.tar.gz | tar xz
-# RUN cp mathsat-5.6.3-linux-x86_64/bin/mathsat rootfs/usr/local/bin
-
-# Set executable and run tests
-RUN chmod +x rootfs/usr/local/bin/*
-
 FROM debian:buster-20210511 AS toolchain
 ARG PORTABILITY=false
-RUN apt-get update && apt-get install -y libncurses-dev libz-dev \
+RUN apt-get update && apt-get install -y libncurses-dev libz-dev unzip \
     build-essential curl libffi-dev libffi6 libgmp-dev libgmp10 libncurses-dev libncurses5 libtinfo5 libnuma-dev \
     $(if ${PORTABILITY}; then echo git autoconf python3; fi)
 ENV GHCUP_INSTALL_BASE_PREFIX=/opt \
     PATH=/opt/.ghcup/bin:$PATH
 RUN curl -o /usr/local/bin/ghcup "https://downloads.haskell.org/~ghcup/0.1.14/x86_64-linux-ghcup-0.1.14" && \
     chmod +x /usr/local/bin/ghcup
-COPY --from=solvers /solvers/rootfs /
 RUN ghcup install cabal --set
 ENV PATH=/root/.cabal/bin:$PATH
 ADD ./cryptol-remote-api/ghc-portability.patch .
@@ -101,6 +56,9 @@ RUN cabal v2-update && \
 ENV PATH=/usr/local/bin:/cryptol/rootfs/usr/local/bin:$PATH
 RUN mkdir -p rootfs/"${CRYPTOLPATH}" \
     && cp -r lib/* rootfs/"${CRYPTOLPATH}"
+WORKDIR /cryptol/rootfs/usr/local/bin
+RUN curl -sL -o solvers.zip "https://github.com/GaloisInc/what4-solvers/releases/download/snapshot-20210917/ubuntu-18.04-bin.zip" && \
+    unzip solvers.zip && rm solvers.zip && chmod +x *
 USER root
 RUN chown -R root:root /cryptol/rootfs
 
@@ -110,7 +68,6 @@ RUN apt-get update \
     && apt-get clean && rm -rf /var/lib/apt/lists/*
 RUN useradd -m cryptol && chown -R cryptol:cryptol /home/cryptol
 COPY --from=build /cryptol/rootfs /
-COPY --from=solvers /solvers/rootfs /
 USER cryptol
 ENV LANG=C.UTF-8 \
     LC_ALL=C.UTF-8