diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4e8a58757a4a2b5a074d304688f57530529ba915..cd8ae8e003b56b1d4124caf6baddc4fa4d5798ba 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -8,6 +8,7 @@ include:
       versions:
         - 7.4.0
         - 7.x
+        - 8.x
   # FIXME: enable remote builds
   #- component: "${CI_SERVER_HOST}/ci/component/bazelisk/config@v1.2.0"
   #  inputs:
diff --git a/labgrid/config/rule.bzl b/labgrid/config/rule.bzl
index ede3586c69c5f179b2d33e4721d5ba56a8f2329a..a79a0f9f1b154904b45637added93ab4c6e7204d 100644
--- a/labgrid/config/rule.bzl
+++ b/labgrid/config/rule.bzl
@@ -91,12 +91,12 @@ ATTRS = {
 def _expand(ctx, data, value):
     value = value.replace("$(location", "$(rlocationpath")
     value = ctx.expand_location(value, targets = data)
+    separator = ctx.label.repo_name[-1]
     for k, v in ctx.var.items():
-        value = value.replace("$({})".format(k), _runfile(v))
+        value = value.replace("$({})".format(k), _runfile(v, separator))
     return value
 
-# FIXME: separator changes to `+` on Bazel 8+
-def _runfile(value, separator = "~"):
+def _runfile(value, separator):
     # Non-runfile value
     if not value.startswith("bazel-out/"):
         return value