diff --git a/tests/libtest.sh b/tests/libtest.sh
index 592d16c4f..fd96cfd21 100644
--- a/tests/libtest.sh
+++ b/tests/libtest.sh
@@ -136,13 +136,16 @@ if [ x${USE_SYSTEMDIR-} == xyes ] ; then
     export FL_DIR=${SYSTEMDIR}
     export U=
     export INVERT_U=--user
-    if [ x${UID} == x0 ] ; then
-        # If running as root (which happens on some build machines), the
-        # system-helper will not be used, and hence the fallback cache dir will
-        # be used in _flatpak_dir_ensure_repo().
-        export FL_CACHE_DIR=$FL_DIR/repo/tmp/cache
-    else
+    if [ x${HAVE_SYSTEM_HELPER-} == x1 ] && [ x${UID} != x0 ] ; then
+        # If system helper is compiled during build and will actually be
+        # used at runtime eg. UID != 0, Flatpak stores summary caches
+        # in the user's XDG cache directory
         export FL_CACHE_DIR=${XDG_CACHE_HOME}/flatpak/system-cache
+    else
+        # If the system helper is unavailable at build time, or it
+        # cannot be used eg. UID == 0 Flatpak uses the repo-local cache
+        # directory.
+        export FL_CACHE_DIR=$FL_DIR/repo/tmp/cache
     fi
 else
     export FL_DIR=${USERDIR}
diff --git a/tests/meson.build b/tests/meson.build
index a0942df37..53f8656de 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -31,6 +31,7 @@ tests_environment = {
   'FLATPAK_BWRAP' : env_flatpak_bwrap,
   'FLATPAK_DBUSPROXY' : env_flatpak_dbusproxy,
   'HAVE_SECCOMP' : libseccomp_dep.found() ? '1' : '0',
+  'HAVE_SYSTEM_HELPER' : build_system_helper ? '1' : '0',
 }
 
 tests_environment_prepend = {