diff --git a/src/libpriv/rpmostree-core.cxx b/src/libpriv/rpmostree-core.cxx
index 1e6af8edaa..9cc872b27b 100644
--- a/src/libpriv/rpmostree-core.cxx
+++ b/src/libpriv/rpmostree-core.cxx
@@ -4062,6 +4062,55 @@ rpmostree_context_assemble (RpmOstreeContext *self, GCancellable *cancellable, G
   if (!build_rootfs_usrlinks (self, error))
     return FALSE;
 
+  /* This is purely for making it easier for people to test out the
+   * state-overlay stuff until it's stabilized and part of base composes. */
+  if (g_getenv ("RPMOSTREE_EXPERIMENTAL_FORCE_OPT_USRLOCAL_OVERLAY"))
+    {
+      rpmostree_output_message (
+          "Enabling experimental state overlay support for /opt and /usr/local");
+
+      struct stat stbuf;
+
+      if (!glnx_fstatat_allow_noent (tmprootfs_dfd, "opt", &stbuf, AT_SYMLINK_NOFOLLOW, error))
+        return FALSE;
+      if (errno == ENOENT || (errno == 0 && S_ISLNK (stbuf.st_mode)))
+        {
+          if (errno == 0 && !glnx_unlinkat (tmprootfs_dfd, "opt", 0, error))
+            return FALSE;
+          if (symlinkat ("usr/lib/opt", tmprootfs_dfd, "opt") < 0)
+            return glnx_throw_errno_prefix (error, "symlinkat(/opt)");
+        }
+
+      if (!glnx_fstatat_allow_noent (tmprootfs_dfd, "usr/local", &stbuf, AT_SYMLINK_NOFOLLOW,
+                                     error))
+        return FALSE;
+      if (errno == ENOENT || (errno == 0 && S_ISLNK (stbuf.st_mode)))
+        {
+          if (errno == 0 && !glnx_unlinkat (tmprootfs_dfd, "usr/local", 0, error))
+            return FALSE;
+          if (mkdirat (tmprootfs_dfd, "usr/local", 0755) < 0)
+            return glnx_throw_errno_prefix (error, "mkdirat(/usr/local)");
+        }
+
+      if (!glnx_shutil_mkdir_p_at (tmprootfs_dfd, "usr/lib/systemd/system/local-fs.target.wants",
+                                   0755, cancellable, error))
+        return FALSE;
+
+      if (symlinkat ("ostree-state-overlay@usr-lib-opt.service", tmprootfs_dfd,
+                     "usr/lib/systemd/system/local-fs.target.wants/"
+                     "ostree-state-overlay@usr-lib-opt.service")
+              < 0
+          && errno != EEXIST)
+        return glnx_throw_errno_prefix (error, "enabling ostree-state-overlay for /usr/lib/opt");
+
+      if (symlinkat (
+              "ostree-state-overlay@usr-local.service", tmprootfs_dfd,
+              "usr/lib/systemd/system/local-fs.target.wants/ostree-state-overlay@usr-local.service")
+              < 0
+          && errno != EEXIST)
+        return glnx_throw_errno_prefix (error, "enabling ostree-state-overlay for /usr/local");
+    }
+
   /* We need up to date labels; the set of things needing relabeling
    * will have been calculated in sort_packages()
    */
diff --git a/tests/kolainst/destructive/state-overlays b/tests/kolainst/destructive/state-overlays
new file mode 100755
index 0000000000..d7f7c418b1
--- /dev/null
+++ b/tests/kolainst/destructive/state-overlays
@@ -0,0 +1,98 @@
+#!/bin/bash
+## kola:
+##   tags: "needs-internet"
+
+set -euo pipefail
+
+. ${KOLA_EXT_DATA}/libtest.sh
+
+rm -rf /etc/yum.repos.d/*
+cat > /etc/yum.repos.d/vmcheck.repo << EOF
+[test-repo]
+name=test-repo
+baseurl=file:///${KOLA_EXT_DATA}/rpm-repos/0
+gpgcheck=0
+enabled=1
+EOF
+
+
+case "${AUTOPKGTEST_REBOOT_MARK:-}" in
+  "")
+    # XXX: until ostree v2024.1 hits FCOS
+    ostree_ver=$(rpm -q ostree  --qf '%{version}')
+    if [ "${ostree_ver}" != "2024.1" ] && \
+       [ "$(echo -e "${ostree_ver}\n2024.1" | sort -V | tail -n1)" = "2024.1" ]; then
+      rpm-ostree override replace https://bodhi.fedoraproject.org/updates/FEDORA-2024-6c7480dd2f
+    fi
+
+    # FCOS doesn't enable opt-usrlocal-overlays so use the hack instead
+    mkdir -p /etc/systemd/system/rpm-ostreed.service.d/
+    cat > /etc/systemd/system/rpm-ostreed.service.d/state-overlay.conf <<EOF
+[Service]
+Environment=RPMOSTREE_EXPERIMENTAL_FORCE_OPT_USRLOCAL_OVERLAY=1
+EOF
+
+    # This script itself is in /usr/local, so we need to move it back on top
+    # of the overlay. This simultaneously demos one way upgrading nodes could
+    # retain content if we turn on opt-usrlocal-overlays in FCOS.
+    cat > /etc/systemd/system/move-usr-local.service <<EOF
+[Unit]
+Description=Move Previous /usr/local content back into /usr/local
+After=local-fs.target
+After=systemd-tmpfiles-setup.service
+Before=kola-runext.service
+
+[Service]
+Type=oneshot
+# I previously used rsync here to sync all of /var/usrlocal, but hit SELinux
+# issues; it seems like it runs as rsync_t which can't do things on top of
+# overlay? To investigate...
+ExecStart=cp /var/usrlocal/bin/kola-runext-state-overlays /usr/local/bin/
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target
+EOF
+    systemctl daemon-reload
+    systemctl restart rpm-ostreed
+    systemctl enable move-usr-local.service
+
+    rpm-ostree install test-opt
+
+    /tmp/autopkgtest-reboot 1
+    ;;
+  1)
+    test -f /opt/megacorp/bin/test-opt
+    test -f /opt/megacorp/lib/mylib
+    test -d /opt/megacorp/state
+
+    /opt/megacorp/bin/test-opt > /tmp/out.txt
+    assert_file_has_content /tmp/out.txt 'test-opt'
+    assert_file_has_content /opt/megacorp/lib/mylib 'lib1'
+
+    # add some state files
+    echo 'foobar' > /opt/megacorp/state/mystate
+
+    # change some base files
+    echo 'badlib' > /opt/megacorp/lib/mylib
+    /tmp/autopkgtest-reboot 2
+    ;;
+  2)
+    # check our state is still there
+    assert_file_has_content /opt/megacorp/state/mystate 'foobar'
+    assert_file_has_content /opt/megacorp/lib/mylib 'badlib'
+    
+    # upgrade to -2
+    sed -i -e 's,rpm-repos/0,rpm-repos/1,' /etc/yum.repos.d/vmcheck.repo
+    rpm-ostree upgrade
+    /tmp/autopkgtest-reboot 3
+    ;;
+  3)
+    # check our state is still there
+    assert_file_has_content /opt/megacorp/state/mystate 'foobar'
+
+    # but base content has been reset
+    assert_file_has_content /opt/megacorp/lib/mylib 'lib2'
+    ;;
+  *) echo "unexpected mark: ${AUTOPKGTEST_REBOOT_MARK}"; exit 1;;
+esac
diff --git a/tests/kolainst/kolainst-build.sh b/tests/kolainst/kolainst-build.sh
index 544e3f8d49..8ed020f163 100755
--- a/tests/kolainst/kolainst-build.sh
+++ b/tests/kolainst/kolainst-build.sh
@@ -96,6 +96,13 @@ build_module_defaults foomodular \
 build_rpm zincati version 99.99 release 2
 build_rpm zincati version 99.99 release 3
 
+# An RPM that installs in /opt
+build_rpm test-opt \
+             install "mkdir -p %{buildroot}/opt/megacorp/{bin,lib,state}
+                      install %{name} %{buildroot}/opt/megacorp/bin
+                      echo lib1 > %{buildroot}/opt/megacorp/lib/mylib" \
+             files "/opt/megacorp"
+
 mv ${test_tmpdir}/yumrepo/* ${test_tmpdir}/rpm-repos/${repover}
 
 # To test remote override replace update
@@ -111,6 +118,14 @@ build_rpm pkgsystemd \
   install "mkdir -p %{buildroot}/usr/lib/systemd/system 
            install %{name}.service %{buildroot}/usr/lib/systemd/system" \
   files "/usr/lib/systemd/system/%{name}.service"
+
+# to test updates to RPMs that install in /opt
+build_rpm test-opt release 2 \
+             install "mkdir -p %{buildroot}/opt/megacorp/{bin,lib,state}
+                      install %{name} %{buildroot}/opt/megacorp/bin
+                      echo lib2 > %{buildroot}/opt/megacorp/lib/mylib" \
+             files "/opt/megacorp"
+
 mv ${test_tmpdir}/yumrepo/* ${test_tmpdir}/rpm-repos/${repover}
 
 # Create an empty repo when we want to test inability to find a package