diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 597846c..d7b4cd4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,6 +30,22 @@ jobs:
           bundler-cache: true
       - run: bundle exec rake
 
+  cruby-nokogiri-system-libraries:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.1"
+      - name: Install nokogiri with system libraries
+        run: |
+          sudo apt install pkg-config libxml2-dev libxslt-dev
+          bundle config set force_ruby_platform true
+          bundle config build.nokogiri --enable-system-libraries
+          bundle install
+          bundle exec nokogiri -v
+      - run: bundle exec rake
+
   jruby:
     continue-on-error: true # nokogiri on jruby has different behavior
     strategy:
diff --git a/test/sanitizer_test.rb b/test/sanitizer_test.rb
index 241564c..1de5a99 100644
--- a/test/sanitizer_test.rb
+++ b/test/sanitizer_test.rb
@@ -505,7 +505,13 @@ def test_uri_escaping_of_href_attr_in_a_tag_in_safe_list_sanitizer
 
     text = safe_list_sanitize(html)
 
-    assert_equal %{<a href=\"examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com\">test</a>}, text
+    acceptable_results = [
+      # nokogiri w/vendored+patched libxml2
+      %{<a href="examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com">test</a>},
+      # nokogiri w/ system libxml2
+      %{<a href="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>},
+    ]
+    assert_includes(acceptable_results, text)
   end
 
   def test_uri_escaping_of_src_attr_in_a_tag_in_safe_list_sanitizer
@@ -515,7 +521,13 @@ def test_uri_escaping_of_src_attr_in_a_tag_in_safe_list_sanitizer
 
     text = safe_list_sanitize(html)
 
-    assert_equal %{<a src=\"examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com\">test</a>}, text
+    acceptable_results = [
+      # nokogiri w/vendored+patched libxml2
+      %{<a src="examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com">test</a>},
+      # nokogiri w/system libxml2
+      %{<a src="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>},
+    ]
+    assert_includes(acceptable_results, text)
   end
 
   def test_uri_escaping_of_name_attr_in_a_tag_in_safe_list_sanitizer
@@ -525,7 +537,13 @@ def test_uri_escaping_of_name_attr_in_a_tag_in_safe_list_sanitizer
 
     text = safe_list_sanitize(html)
 
-    assert_equal %{<a name=\"examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com\">test</a>}, text
+    acceptable_results = [
+      # nokogiri w/vendored+patched libxml2
+      %{<a name="examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com">test</a>},
+      # nokogiri w/system libxml2
+      %{<a name="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>},
+    ]
+    assert_includes(acceptable_results, text)
   end
 
   def test_uri_escaping_of_name_action_in_a_tag_in_safe_list_sanitizer
@@ -535,7 +553,13 @@ def test_uri_escaping_of_name_action_in_a_tag_in_safe_list_sanitizer
 
     text = safe_list_sanitize(html, attributes: ['action'])
 
-    assert_equal %{<a action=\"examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com\">test</a>}, text
+    acceptable_results = [
+      # nokogiri w/vendored+patched libxml2
+      %{<a action="examp&lt;!--%22%20unsafeattr=foo()&gt;--&gt;le.com">test</a>},
+      # nokogiri w/system libxml2
+      %{<a action="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>},
+    ]
+    assert_includes(acceptable_results, text)
   end
 
   def test_exclude_node_type_processing_instructions