diff --git a/.github/workflows/ubuntu-rubygems.yml b/.github/workflows/ubuntu-rubygems.yml
index 9ea78e9c8b34..2f99762db45c 100644
--- a/.github/workflows/ubuntu-rubygems.yml
+++ b/.github/workflows/ubuntu-rubygems.yml
@@ -36,6 +36,11 @@ jobs:
       - name: Run Test
         run: rake test
         if: "!startsWith(matrix.ruby.name, 'truffleruby') && !startsWith(matrix.ruby.name, 'jruby')"
+      - name: Run Test (--disable-gems)
+        env:
+          RUBYOPT: --disable-gems
+        run: rake test
+        if: "!startsWith(matrix.ruby.name, 'truffleruby') && !startsWith(matrix.ruby.name, 'jruby')"
       - name: Run Test (JRuby)
         run: JRUBY_OPTS=--debug rake test
         if: startsWith(matrix.ruby.name, 'jruby')