diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 47502364..c74a5183 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -30,6 +30,7 @@ jobs:
         - ruby: '3.0'
           rails_version: '7.0.4.1'
     env:
+      BLACKLIGHT_VERSION: "~> 7.0" # only test on BL 7 for now
       RAILS_VERSION: ${{ matrix.rails_version }}
       ENGINE_CART_RAILS_OPTIONS: "--skip-git --skip-listen --skip-spring --skip-keeps --skip-action-cable --skip-coffee --skip-test ${{ matrix.engine_cart_rails_options }}"
     steps:
diff --git a/Gemfile b/Gemfile
index fc0ada35..dc26db92 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,6 +9,14 @@ group :test do
   gem 'activerecord-jdbcsqlite3-adapter', platform: :jruby
 end
 
+# While gemspec allows BL8 and some people are using BL8... the build
+# has never actually passed on BL8 yet. We may choose to run tests on
+# a blacklight version other than the latest allowed by gemspec, to get
+# tests to pass, or to test on older BL still supported here.
+if ENV['BLACKLIGHT_VERSION']
+  gem "blacklight", ENV['BLACKLIGHT_VERSION']
+end
+
 # BEGIN ENGINE_CART BLOCK
 # engine_cart: 2.5.0
 # engine_cart stanza: 2.5.0