diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 87fdb132..2b6b19ee 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -53,7 +53,7 @@ jobs:
           sudo apt update
       - name: Install system dependencies
         run: |
-          sudo apt install libmagic-dev libgmp-dev libblas-dev liblapack-dev libcairo2-dev libpango1.0-dev libzmq3-dev
+          sudo apt install libmagic-dev libgmp-dev libblas-dev liblapack-dev libcairo2-dev libpango1.0-dev libzmq3-dev jq
       - name: Set up Python
         uses: actions/setup-python@v1
         with:
diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
index 425fb705..437a1d94 100644
--- a/.github/workflows/nix.yml
+++ b/.github/workflows/nix.yml
@@ -35,7 +35,7 @@ jobs:
       matrix:
         versions:
           - compiler: 'ghc884'
-          - compiler: 'ghc8102'
+          - compiler: 'ghc8104'
     steps:
     - uses: actions/checkout@v2
     - uses: cachix/install-nix-action@v12
@@ -48,5 +48,8 @@ jobs:
         -I nixpkgs=https://github.com/NixOS/nixpkgs/tarball/nixos-20.09 \
         release.nix \
         --argstr compiler ${{ matrix.versions.compiler }}
-        test/acceptance.nbconvert.sh result/bin/ihaskell-nbconvert
+        nix-shell \
+        -I nixpkgs=https://github.com/NixOS/nixpkgs/tarball/nixos-20.09 \
+        -p jq --run \
+        'test/acceptance.nbconvert.sh result/bin/ihaskell-nbconvert'
 
diff --git a/test/acceptance.nbconvert.sh b/test/acceptance.nbconvert.sh
index 4f0cc39e..c12d3ec3 100755
--- a/test/acceptance.nbconvert.sh
+++ b/test/acceptance.nbconvert.sh
@@ -3,7 +3,8 @@
 # Run nbconvert acceptance tests
 # ------------------------------
 #
-# This script must be called from the root directory of IHaskell.
+# This script must be called from the root directory of IHaskell. It requires
+# `jq` to be available in the $PATH.
 #
 # Positional arguments to this script are the invocation for `nbconvert`.
 # For example:
@@ -27,7 +28,11 @@
 
 set -euo pipefail
 
-$* --to=notebook --execute --allow-errors --stdout test/acceptance.nbconvert.in.ipynb > test/acceptance.nbconvert.out.ipynb
+$* --to=notebook --execute --allow-errors --stdout --nbformat=4 test/acceptance.nbconvert.in.ipynb > test/acceptance.nbconvert.out.ipynb
 
-diff <(grep -v -e 'version' -e 'Line ' -e 'Integral' test/acceptance.nbconvert.in.ipynb) <(grep -v -e 'version' -e 'Line ' -e 'Integral' test/acceptance.nbconvert.out.ipynb)
+diff \
+  <(grep -v -e 'version' -e 'Line ' -e 'Integral' -e 'Num'  \
+    <(cat test/acceptance.nbconvert.in.ipynb | jq '{"cells": .cells | map(del(.metadata.execution)), "metadata": .metadata}')) \
+  <(grep -v -e 'version' -e 'Line ' -e 'Integral' -e 'Num'  \
+    <(cat test/acceptance.nbconvert.out.ipynb | jq '{"cells": .cells | map(del(.metadata.execution)), "metadata": .metadata}'))