diff --git a/lib/gitlab/string_regex_marker.rb b/lib/gitlab/string_regex_marker.rb
new file mode 100644
index 0000000000000000000000000000000000000000..7ebf1c0428ca2786435c73e98b0489a56b7f71e3
--- /dev/null
+++ b/lib/gitlab/string_regex_marker.rb
@@ -0,0 +1,13 @@
+module Gitlab
+  class StringRegexMarker < StringRangeMarker
+    def mark(regex, group: 0, &block)
+      regex_match = raw_line.match(regex)
+      return rich_line unless regex_match
+
+      begin_index, end_index = regex_match.offset(group)
+      name_range = begin_index..(end_index - 1)
+
+      super([name_range], &block)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/string_range_marker_spec.rb b/spec/lib/gitlab/string_range_marker_spec.rb
index 45b4d4af20613b81b2e5389e4bf87383e01666b0..7c77772b3f6e80b54724f94a33a76db467310bb1 100644
--- a/spec/lib/gitlab/string_range_marker_spec.rb
+++ b/spec/lib/gitlab/string_range_marker_spec.rb
@@ -6,7 +6,7 @@ describe Gitlab::StringRangeMarker, lib: true do
       let(:raw)  { "abc <def>" }
       let(:rich) { %{<span class="abc">abc</span><span class="space"> </span><span class="def">&lt;def&gt;</span>}.html_safe }
       let(:inline_diffs) { [2..5] }
-      let(:subject) do
+      subject do
         described_class.new(raw, rich).mark(inline_diffs) do |text, left:, right:|
           "LEFT#{text}RIGHT"
         end
@@ -21,7 +21,7 @@ describe Gitlab::StringRangeMarker, lib: true do
     context "when the rich text is not html safe" do
       let(:raw)  { "abc <def>" }
       let(:inline_diffs) { [2..5] }
-      let(:subject) do
+      subject do
         described_class.new(raw).mark(inline_diffs) do |text, left:, right:|
           "LEFT#{text}RIGHT"
         end
diff --git a/spec/lib/gitlab/string_regex_marker_spec.rb b/spec/lib/gitlab/string_regex_marker_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..2f5cf6c6e3b61645320ac9169c94483aab6545f3
--- /dev/null
+++ b/spec/lib/gitlab/string_regex_marker_spec.rb
@@ -0,0 +1,18 @@
+require 'spec_helper'
+
+describe Gitlab::StringRegexMarker, lib: true do
+  describe '#mark' do
+    let(:raw)  { %{"name": "AFNetworking"} }
+    let(:rich) { %{<span class="key">"name"</span><span class="punctuation">: </span><span class="value">"AFNetworking"</span>}.html_safe }
+    subject do
+      described_class.new(raw, rich).mark(/"[^"]+":\s*"(?<name>[^"]+)"/, group: :name) do |text, left:, right:|
+        %{<a href="#">#{text}</a>}
+      end
+    end
+
+    it 'marks the inline diffs' do
+      expect(subject).to eq(%{<span class="key">"name"</span><span class="punctuation">: </span><span class="value">"<a href="#">AFNetworking</a>"</span>})
+      expect(subject).to be_html_safe
+    end
+  end
+end