diff --git a/.github/workflows/scripts/qemu-3-deps-vm.sh b/.github/workflows/scripts/qemu-3-deps-vm.sh
index 8f684f49a..c8e1a015a 100755
--- a/.github/workflows/scripts/qemu-3-deps-vm.sh
+++ b/.github/workflows/scripts/qemu-3-deps-vm.sh
@@ -120,6 +120,11 @@ function rhel() {
     kernel-devel python3-setuptools qemu-guest-agent rng-tools rpcgen \
     rpm-build rsync samba strace sysstat systemd watchdog wget xfsprogs-devel \
     xxhash zlib-devel
+
+  # These are needed for building Lustre.  We only install these on EL VMs since
+  # we don't plan to test build Lustre on other platforms.
+  sudo dnf install -y libnl3-devel libyaml-devel libmount-devel
+
   echo "##[endgroup]"
 }
 
diff --git a/.github/workflows/scripts/qemu-6-lustre-tests-vm.sh b/.github/workflows/scripts/qemu-6-lustre-tests-vm.sh
new file mode 100755
index 000000000..ff3f0a356
--- /dev/null
+++ b/.github/workflows/scripts/qemu-6-lustre-tests-vm.sh
@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+
+######################################################################
+# 6) Test if Lustre can still build against ZFS
+######################################################################
+set -e
+
+# Build from the latest Lustre tag rather than the master branch.  We do this
+# under the assumption that master is going to have a lot of churn thus will be
+# more prone to breaking the build than a point release.  We don't want ZFS
+# PR's reporting bad test results simply because upstream Lustre accidentally
+# broke their build.
+#
+# Skip any RC tags, or any tags where the last version digit is 50 or more.
+# Versions with 50 or more are development versions of Lustre.
+repo=https://github.com/lustre/lustre-release.git
+tag="$(git ls-remote --refs --exit-code --sort=version:refname --tags $repo | \
+	awk -F '_' '/-RC/{next}; /refs\/tags\/v/{if ($NF < 50){print}}' | \
+	tail -n 1 | sed 's/.*\///')"
+
+echo "Cloning Lustre tag $tag"
+git clone --depth 1 --branch "$tag" "$repo"
+
+cd lustre-release
+
+# Include Lustre patches to build against master/zfs-2.4.x.  Once these
+# patches are merged we can remove these lines.
+patches=('https://review.whamcloud.com/changes/fs%2Flustre-release~62101/revisions/2/patch?download'
+	'https://review.whamcloud.com/changes/fs%2Flustre-release~63267/revisions/9/patch?download')
+
+for p in "${patches[@]}" ; do
+	curl $p | base64 -d > patch
+	patch -p1 < patch || true
+done
+
+echo "Configure Lustre"
+./autogen.sh
+# EL 9 needs '--disable-gss-keyring'
+./configure --with-zfs --disable-gss-keyring
+echo "Building Lustre RPMs"
+make rpms
+ls *.rpm
+
+# There's only a handful of Lustre RPMs we actually need to install
+lustrerpms="$(ls *.rpm | grep -E 'kmod-lustre-osd-zfs-[0-9]|kmod-lustre-[0-9]|lustre-osd-zfs-mount-[0-9]')"
+echo "Installing: $lustrerpms"
+sudo dnf -y install $lustrerpms
+sudo modprobe -v lustre
+
+# Should see some Lustre lines in dmesg
+sudo dmesg | grep -Ei 'lnet|lustre'
diff --git a/.github/workflows/scripts/qemu-6-tests.sh b/.github/workflows/scripts/qemu-6-tests.sh
index a1e6bc1c6..6c3508678 100755
--- a/.github/workflows/scripts/qemu-6-tests.sh
+++ b/.github/workflows/scripts/qemu-6-tests.sh
@@ -4,7 +4,9 @@
 # 6) load openzfs module and run the tests
 #
 # called on runner:  qemu-6-tests.sh
-# called on qemu-vm: qemu-6-tests.sh $OS $2/$3
+# called on qemu-vm: qemu-6-tests.sh $OS $2 $3 [--lustre] [quick|default]
+#
+# --lustre: Test build lustre in addition to the normal tests
 ######################################################################
 
 set -eu
@@ -38,6 +40,16 @@ function prefix() {
   fi
 }
 
+function do_lustre_build() {
+  local rc=0
+  $HOME/zfs/.github/workflows/scripts/qemu-6-lustre-tests-vm.sh &> /var/tmp/lustre.txt || rc=$?
+  echo "$rc" > /var/tmp/lustre-exitcode.txt
+  if [ "$rc" != "0" ] ; then
+      echo "$rc" > /var/tmp/tests-exitcode.txt
+  fi
+}
+export -f do_lustre_build
+
 # called directly on the runner
 if [ -z ${1:-} ]; then
   cd "/var/tmp"
@@ -49,8 +61,18 @@ if [ -z ${1:-} ]; then
 
   for ((i=1; i<=VMs; i++)); do
     IP="192.168.122.1$i"
+
+    # We do an additional test build of Lustre against ZFS if we're vm2
+    # on almalinux*.  At the time of writing, the vm2 tests were
+    # completing roughly 15min before the vm1 tests, so it makes sense
+    # to have vm2 do the build.
+    extra=""
+    if [[ "$OS" == almalinux* ]] && [[ "$i" == "2" ]] ; then
+        extra="--lustre"
+    fi
+
     daemonize -c /var/tmp -p vm${i}.pid -o vm${i}log.txt -- \
-      $SSH zfs@$IP $TESTS $OS $i $VMs $CI_TYPE
+      $SSH zfs@$IP $TESTS $OS $i $VMs $extra $CI_TYPE
     # handly line by line and add info prefix
     stdbuf -oL tail -fq vm${i}log.txt \
       | while read -r line; do prefix "$i" "$line"; done &
@@ -70,9 +92,31 @@ if [ -z ${1:-} ]; then
   exit 0
 fi
 
-# this part runs inside qemu vm
+
+#############################################
+# Everything from here on runs inside qemu vm
+#############################################
+
+# Process cmd line args
+OS="$1"
+shift
+NUM="$1"
+shift
+DEN="$1"
+shift
+
+BUILD_LUSTRE=0
+if [ "$1" == "--lustre" ] ; then
+  BUILD_LUSTRE=1
+  shift
+fi
+
+if [ "$1" == "quick" ] ; then
+  export RUNFILES="sanity.run"
+fi
+
 export PATH="$PATH:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/sbin:/usr/local/bin"
-case "$1" in
+case "$OS" in
   freebsd*)
     TDIR="/usr/local/share/zfs"
     sudo kldstat -n zfs 2>/dev/null && sudo kldunload zfs
@@ -96,7 +140,7 @@ case "$1" in
 esac
 
 # Distribution-specific settings.
-case "$1" in
+case "$OS" in
   almalinux9|almalinux10|centos-stream*)
     # Enable io_uring on Enterprise Linux 9 and 10.
     sudo sysctl kernel.io_uring_disabled=0 > /dev/null
@@ -109,16 +153,25 @@ case "$1" in
     ;;
 esac
 
+# Lustre calls a number of exported ZFS module symbols.  To make sure we don't
+# change the symbols and break Lustre, do a quick Lustre build of the latest
+# released Lustre against ZFS.
+#
+# Note that we do the Lustre test build in parallel with ZTS.  ZTS isn't very
+# CPU intensive, so we can use idle CPU cycles "guilt free" for the build.
+# The Lustre build on its own takes ~15min.
+if [ "$BUILD_LUSTRE" == "1" ] ; then
+  do_lustre_build &
+fi
+
 # run functional testings and save exitcode
 cd /var/tmp
-TAGS=$2/$3
-if [ "$4" == "quick" ]; then
-  export RUNFILES="sanity.run"
-fi
+TAGS=$NUM/$DEN
 sudo dmesg -c > dmesg-prerun.txt
 mount > mount.txt
 df -h > df-prerun.txt
 $TDIR/zfs-tests.sh -vKO -s 3GB -T $TAGS
+
 RV=$?
 df -h > df-postrun.txt
 echo $RV > tests-exitcode.txt
diff --git a/.github/workflows/scripts/qemu-8-summary.sh b/.github/workflows/scripts/qemu-8-summary.sh
index 7d1e16567..aa78b475e 100755
--- a/.github/workflows/scripts/qemu-8-summary.sh
+++ b/.github/workflows/scripts/qemu-8-summary.sh
@@ -31,6 +31,12 @@ EOF
   rm -f tmp$$
 }
 
+function showfile_tail() {
+  echo "##[group]$2 (final lines)"
+  tail -n 40 $1
+  echo "##[endgroup]"
+}
+
 # overview
 cat /tmp/summary.txt
 echo ""
@@ -46,6 +52,20 @@ fi
 echo -e "\nFull logs for download:\n    $1\n"
 
 for ((i=1; i<=VMs; i++)); do
+
+  # Print Lustre build test results (the build is only done on vm2)
+  if [ -f vm$i/lustre-exitcode.txt ] ; then
+    rv=$(< vm$i/lustre-exitcode.txt)
+    if [ $rv = 0 ]; then
+      vm="vm$i"
+    else
+      vm="vm$i"
+      touch /tmp/have_failed_tests
+    fi
+    file="vm$i/lustre.txt"
+    test -s "$file" && showfile_tail "$file" "$vm: Lustre build"
+  fi
+
   rv=$(cat vm$i/tests-exitcode.txt)
 
   if [ $rv = 0 ]; then