diff --git a/test/TEST-04-JOURNAL/test.sh b/test/TEST-04-JOURNAL/test.sh
index 507dace514..96fc8b7049 100755
--- a/test/TEST-04-JOURNAL/test.sh
+++ b/test/TEST-04-JOURNAL/test.sh
@@ -13,7 +13,11 @@ test_append_files() {
     mkdir -p "$workspace/test-journals/"
     cp -av "${TEST_BASE_DIR:?}/test-journals/"* "$workspace/test-journals/"
 
-    inst_binary unzstd
+    image_install curl unzstd
+    image_install -o openssl
+    # Necessary for RH-based systems, otherwise MHD fails with:
+    #   microhttpd: Failed to initialise TLS session.
+    image_install -o /etc/crypto-policies/back-ends/gnutls.config
 }
 
 do_test "$@"
diff --git a/test/units/testsuite-04.journal-gatewayd.sh b/test/units/testsuite-04.journal-gatewayd.sh
new file mode 100755
index 0000000000..1efdc3cae0
--- /dev/null
+++ b/test/units/testsuite-04.journal-gatewayd.sh
@@ -0,0 +1,116 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+# pipefail is disabled intentionally, as `curl | grep -q` is very SIGPIPE happy
+
+if [[ ! -x /usr/lib/systemd/systemd-journal-gatewayd ]]; then
+    echo "Built without systemd-journal-gatewayd support, skipping the test"
+    exit 0
+fi
+
+TEST_MESSAGE="-= This is a test message $RANDOM =-"
+TEST_TAG="$(systemd-id128 new)"
+
+echo "$TEST_MESSAGE" | systemd-cat -t "$TEST_TAG"
+journalctl --sync
+TEST_CURSOR="$(journalctl -q -t "$TEST_TAG" -n 0 --show-cursor | awk '{ print $3; }')"
+BOOT_CURSOR="$(journalctl -q -b -n 0 --show-cursor | awk '{ print $3; }')"
+
+/usr/lib/systemd/systemd-journal-gatewayd --version
+/usr/lib/systemd/systemd-journal-gatewayd --help
+
+# Default configuration (HTTP, socket activated)
+systemctl start systemd-journal-gatewayd.socket
+
+# /browse
+# We should get redirected to /browse by default
+curl -Lfs http://localhost:19531 | grep -qF "<title>Journal</title>"
+curl -Lfs http://localhost:19531/browse | grep -qF "<title>Journal</title>"
+(! curl -Lfs http://localhost:19531/foo/bar/baz)
+(! curl -Lfs http://localhost:19531/foo/../../../bar/../baz)
+
+# /entries
+# Accept: text/plain should be the default
+curl -Lfs http://localhost:19531/entries | \
+    grep -qE " $TEST_TAG\[[0-9]+\]: $TEST_MESSAGE"
+curl -Lfs --header "Accept: text/plain" http://localhost:19531/entries | \
+    grep -qE " $TEST_TAG\[[0-9]+\]: $TEST_MESSAGE"
+curl -Lfs --header "Accept: application/json" http://localhost:19531/entries | \
+    jq -se ".[] | select(.MESSAGE == \"$TEST_MESSAGE\")"
+# FIXME: drop the condition once https://github.com/systemd/systemd/issues/28059 is resolved
+if ! systemd-detect-virt -cq; then
+    curl -Lfs --header "Accept: application/json" http://localhost:19531/entries?boot | \
+        jq -se ".[] | select(.MESSAGE == \"$TEST_MESSAGE\")"
+fi
+curl -Lfs --header "Accept: application/json" http://localhost:19531/entries?SYSLOG_IDENTIFIER="$TEST_TAG" | \
+    jq -se "length == 1 and select(.[].MESSAGE == \"$TEST_MESSAGE\")"
+# Show 10 entries starting from $BOOT_CURSOR, skip the first 5
+curl -Lfs --header "Accept: application/json" --header "Range: entries=$BOOT_CURSOR:5:10" http://localhost:19531/entries | \
+    jq -se "length == 10"
+# Check if the specified cursor refers to an existing entry and return just that entry
+curl -Lfs --header "Accept: application/json" --header "Range: entries=$TEST_CURSOR" http://localhost:19531/entries?discrete | \
+    jq -se "length == 1 and select(.[].MESSAGE == \"$TEST_MESSAGE\")"
+# No idea how to properly parse this (jq won't cut it), so let's at least do some sanity checks that every
+# line is either empty or begins with data:
+curl -Lfs --header "Accept: text/event-stream" http://localhost:19531/entries | \
+    awk '!/^(data: \{.+\}|)$/ { exit 1; }'
+# Same thing as journalctl --output=export
+mkdir /tmp/remote-journal
+curl -Lfs --header "Accept: application/vnd.fdo.journal" http://localhost:19531/entries | \
+    /usr/lib/systemd/systemd-journal-remote -o /tmp/remote-journal/system.journal --split-mode=none -
+journalctl --directory=/tmp/remote-journal -t "$TEST_TAG" --grep "$TEST_MESSAGE"
+rm -rf /tmp/remote-journal
+
+# /machine
+curl -Lfs http://localhost:19531/machine | jq
+
+# /fields
+curl -Lfs http://localhost:19531/fields/MESSAGE | grep -qE -- "$TEST_MESSAGE"
+curl -Lfs http://localhost:19531/fields/_TRANSPORT
+(! curl -Lfs http://localhost:19531/fields)
+(! curl -Lfs http://localhost:19531/fields/foo-bar-baz)
+
+systemctl stop systemd-journal-gatewayd.{socket,service}
+
+if ! command -v openssl >/dev/null; then
+    echo "openssl command not available, skipping the HTTPS tests"
+    exit 0
+fi
+
+# Generate a self-signed certificate for systemd-journal-gatewayd
+#
+# Note: older OpenSSL requires a config file with some extra options, unfortunately
+cat >/tmp/openssl.conf <<EOF
+[ req ]
+prompt = no
+distinguished_name = req_distinguished_name
+
+[ req_distinguished_name ]
+C = CZ
+L = Brno
+O = Foo
+OU = Bar
+CN = localhost
+EOF
+openssl req -x509 -nodes -newkey rsa:2048 -sha256 -days 7 \
+            -config /tmp/openssl.conf \
+            -keyout /tmp/key.pem -out /tmp/cert.pem
+# Start HTTPS version of gatewayd via the systemd-socket-activate tool to give it some coverage as well
+systemd-socket-activate --listen=19531 -- \
+    /usr/lib/systemd/systemd-journal-gatewayd \
+        --cert=/tmp/cert.pem \
+        --key=/tmp/key.pem \
+        --file="/var/log/journal/*/*.journal" &
+GATEWAYD_PID=$!
+sleep 1
+
+# Do a limited set of tests, since the underlying code should be the same past the HTTPS transport
+curl -Lfsk https://localhost:19531 | grep -qF "<title>Journal</title>"
+curl -Lfsk https://localhost:19531/entries | \
+    grep -qE " $TEST_TAG\[[0-9]+\]: $TEST_MESSAGE"
+curl -Lfsk --header "Accept: application/json" https://localhost:19531/entries | \
+    jq -se ".[] | select(.MESSAGE == \"$TEST_MESSAGE\")"
+curl -Lfsk https://localhost:19531/machine | jq
+curl -Lfsk https://localhost:19531/fields/_TRANSPORT
+
+kill "$GATEWAYD_PID"