diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f300840a9..9f7c01cb8 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -19,7 +19,7 @@ jobs:
     - uses: dtolnay/rust-toolchain@1.70
     - name: Install deps
       run: |
-        sudo apt install gettext libpcre2-dev python3-pexpect tmux
+        sudo apt install gettext libpcre2-dev python3-pexpect python3-sphinx tmux
         # Generate a locale that uses a comma as decimal separator.
         sudo locale-gen fr_FR.UTF-8
     - name: cmake
diff --git a/tests/checks/check-sphinx.fish b/tests/checks/check-sphinx.fish
new file mode 100644
index 000000000..6b3df6e27
--- /dev/null
+++ b/tests/checks/check-sphinx.fish
@@ -0,0 +1,33 @@
+#RUN: fish_indent=%fish_indent fish=%fish %fish %s
+#REQUIRES: command -v sphinx-build
+
+set -g tmp_dir (mktemp -d)
+
+function build_docs --argument-names builder
+    set -l repo_root (status dirname)/../..
+    set -l docsrc $repo_root/doc_src
+    set -l doctree $tmp_dir/doctree
+    set -l output_dir $tmp_dir/$builder
+    # sphinx-build needs fish_indent in $PATH
+    set -lxp PATH (path dirname $fish_indent)
+    sphinx-build \
+        -j auto \
+        -q \
+        -W \
+        -E \
+        -b $builder \
+        -c $docsrc \
+        -d $doctree \
+        $docsrc \
+        $output_dir
+end
+
+set -l success true
+build_docs man || set -l success false
+build_docs html || set -l success false
+
+rm -r $tmp_dir
+
+if test $success = false
+    exit 1
+end