diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c99f63cf..2e1726cb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ on:
   workflow_dispatch:
 
 env:
-  SOLVER_PKG_VERSION: "snapshot-20220721"
+  SOLVER_PKG_VERSION: "snapshot-20220812"
   # The CACHE_VERSION can be updated to force the use of a new cache if
   # the current cache contents become corrupted/invalid.  This can
   # sometimes happen when (for example) the OS version is changed but
@@ -20,7 +20,7 @@ env:
 
 jobs:
   config:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     outputs:
       name: ${{ steps.config.outputs.name }}
       version: ${{ steps.config.outputs.version }}
@@ -58,7 +58,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, macos-12, windows-2019]
+        os: [ubuntu-22.04, macos-12, windows-2019]
         ghc-version: ["8.8.4", "8.10.7", "9.0.2", "9.2.2"]
         exclude:
           # https://gitlab.haskell.org/ghc/ghc/-/issues/18550
@@ -71,7 +71,7 @@ jobs:
         include:
           # We include one job from an older Ubuntu LTS release to increase our
           # coverage of possible Linux configurations.
-          - os: ubuntu-18.04
+          - os: ubuntu-22.04
             ghc-version: 8.8.4
     outputs:
       test-lib-json: ${{ steps.test-lib.outputs.targets-json }}
@@ -231,12 +231,12 @@ jobs:
       matrix:
         suite: [test-lib]
         target: ${{ fromJson(needs.build.outputs.test-lib-json) }}
-        os: [ubuntu-20.04, macos-12, windows-2019]
+        os: [ubuntu-22.04, macos-12, windows-2019]
         continue-on-error: [false]
         include:
           - suite: rpc
             target: ''
-            os: ubuntu-20.04
+            os: ubuntu-22.04
             continue-on-error: false
           #- suite: rpc
           #  target: ''
@@ -311,7 +311,7 @@ jobs:
           cryptol-remote-api/run_rpc_tests.sh
 
   build-push-image:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     needs: [config]
     if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch' || needs.config.outputs.release == 'true'
     strategy:
diff --git a/Dockerfile b/Dockerfile
index 29a88679..5e0f67ba 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,21 +1,36 @@
-FROM haskell:8.8.4 AS build
+FROM ubuntu:22.04 AS build
 
-RUN apt-get update && apt-get install -y libncurses-dev unzip
+RUN apt-get update && \
+    apt-get install -y \
+      # ghcup requirements
+      build-essential curl libffi-dev libffi8 libgmp-dev libgmp10 libncurses-dev libncurses6 libtinfo6 \
+      # Cryptol dependencies
+      zlib1g-dev \
+      # Miscellaneous
+      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-20220114/ubuntu-18.04-bin.zip"
+RUN curl -o solvers.zip -sL "https://github.com/GaloisInc/what4-solvers/releases/download/snapshot-20220812/ubuntu-22.04-bin.zip"
 RUN unzip solvers.zip && rm solvers.zip && chmod +x *
 WORKDIR /cryptol
-ENV PATH=/cryptol/rootfs/usr/local/bin:$PATH
+ENV PATH=/cryptol/rootfs/usr/local/bin:/home/cryptol/.local/bin:/home/cryptol/.ghcup/bin:$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 /home/cryptol/.local/bin && \
+    curl -L https://downloads.haskell.org/~ghcup/0.1.17.7/x86_64-linux-ghcup-0.1.17.7 -o /home/cryptol/.local/bin/ghcup && \
+    chmod +x /home/cryptol/.local/bin/ghcup
+RUN mkdir -p /home/cryptol/.ghcup && \
+    ghcup --version && \
+    ghcup install cabal 3.6.2.0 && \
+    ghcup install ghc 8.8.4 && \
+    ghcup set ghc 8.8.4
 RUN cabal v2-update && \
     cabal v2-build -j cryptol:exe:cryptol && \
     cp $(cabal v2-exec which cryptol) rootfs/usr/local/bin && \
@@ -33,9 +48,9 @@ RUN mkdir -p rootfs/"${CRYPTOLPATH}" \
 USER root
 RUN chown -R root:root /cryptol/rootfs
 
-FROM debian:buster-20210511-slim
+FROM ubuntu:22.04
 RUN apt-get update \
-    && apt-get install -y libgmp10 libgomp1 libffi6 libncurses6 libtinfo6 libreadline7 \
+    && apt-get install -y libgmp10 libgomp1 libffi8 libncurses6 libtinfo6 libreadline8 \
     && apt-get clean && rm -rf /var/lib/apt/lists/*
 RUN useradd -m cryptol && chown -R cryptol:cryptol /home/cryptol
 COPY --from=build /cryptol/rootfs /
diff --git a/README.md b/README.md
index 88f183c6..5d5647d6 100644
--- a/README.md
+++ b/README.md
@@ -46,7 +46,7 @@ Cryptol currently uses Microsoft Research's [Z3 SMT
 solver](https://github.com/Z3Prover/z3) by default to solve constraints
 during type checking, and as the default solver for the `:sat` and
 `:prove` commands.  Cryptol generally requires the most recent version
-of Z3, but you can see the specific version tested in CI by looking [here](https://github.com/GaloisInc/what4-solvers/releases/tag/snapshot-20220721).
+of Z3, but you can see the specific version tested in CI by looking [here](https://github.com/GaloisInc/what4-solvers/releases/tag/snapshot-20220812).
 
 You can download Z3 binaries for a variety of platforms from their
 [releases page](https://github.com/Z3Prover/z3/releases). If you
@@ -75,8 +75,8 @@ Cryptol builds and runs on various flavors of Linux, Mac OS X, and
 Windows. We regularly build and test it in the following environments:
 
 - macOS 12, 64-bit
-- Ubuntu 18.04, 64-bit
 - Ubuntu 20.04, 64-bit
+- Ubuntu 22.04, 64-bit
 - Windows Server 2019, 64-bit
 
 ## Prerequisites
diff --git a/cryptol-remote-api/Dockerfile b/cryptol-remote-api/Dockerfile
index 225f64dd..0cb6c870 100644
--- a/cryptol-remote-api/Dockerfile
+++ b/cryptol-remote-api/Dockerfile
@@ -1,10 +1,17 @@
 ARG GHCVER="8.10.7"
 ARG GHCVER_BOOTSTRAP="8.10.2"
-FROM debian:buster-20210511 AS toolchain
+FROM ubuntu:22.04 AS toolchain
 ARG PORTABILITY=false
-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)
+RUN apt-get update && \
+    apt-get install -y \
+      # ghcup requirements
+      build-essential curl libffi-dev libffi8 libgmp-dev libgmp10 libncurses-dev libncurses6 libtinfo6 \
+      # Cryptol dependencies
+      zlib1g-dev \
+      # GHC build dependencies
+      $(if ${PORTABILITY}; then echo git autoconf python3 libnuma-dev; fi) \
+      # Miscellaneous
+      unzip
 ENV GHCUP_INSTALL_BASE_PREFIX=/opt \
     PATH=/opt/.ghcup/bin:$PATH
 RUN curl -o /usr/local/bin/ghcup "https://downloads.haskell.org/~ghcup/0.1.17.7/x86_64-linux-ghcup-0.1.17.7" && \
@@ -57,14 +64,14 @@ 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-20220114/ubuntu-18.04-bin.zip" && \
+RUN curl -sL -o solvers.zip "https://github.com/GaloisInc/what4-solvers/releases/download/snapshot-20220812/ubuntu-22.04-bin.zip" && \
     unzip solvers.zip && rm solvers.zip && chmod +x *
 USER root
 RUN chown -R root:root /cryptol/rootfs
 
-FROM debian:buster-20210511-slim
+FROM ubuntu:22.04
 RUN apt-get update \
-    && apt-get install -y libgmp10 libgomp1 libffi6 libncurses6 libtinfo6 libreadline7 libnuma-dev openssl \
+    && apt-get install -y libgmp10 libgomp1 libffi8 libncurses6 libtinfo6 libreadline8 libnuma-dev openssl \
     && apt-get clean && rm -rf /var/lib/apt/lists/*
 RUN useradd -m cryptol && chown -R cryptol:cryptol /home/cryptol
 COPY --from=build /cryptol/rootfs /