diff --git a/lib/gitlab/untrusted_regexp.rb b/lib/gitlab/untrusted_regexp.rb
index 006681654f315bf3a9be9048f99c81341ccd148a..95a1d02e87fcd2006f2fffe3e83b3ae7bd26c3d8 100644
--- a/lib/gitlab/untrusted_regexp.rb
+++ b/lib/gitlab/untrusted_regexp.rb
@@ -18,7 +18,7 @@ class UntrustedRegexp
 
     # recreate Ruby's \R metacharacter
     # https://ruby-doc.org/3.2.2/Regexp.html#class-Regexp-label-Character+Classes
-    BACKSLASH_R = '(\n|\v|\f|\r|\x{0085}|\x{2028}|\x{2029}|\r\n)'
+    BACKSLASH_R = '(\n|\v|\f|\r\n|\r|\x{0085}|\x{2028}|\x{2029})'
 
     delegate :===, :source, to: :regexp
 
diff --git a/lib/gitlab/wiki_pages/front_matter_parser.rb b/lib/gitlab/wiki_pages/front_matter_parser.rb
index 3fd62771a90bdf6d329b8b74729f9006a287d1e3..f796aa6ff0486c1a94d5d499d1d04707fdd460d2 100644
--- a/lib/gitlab/wiki_pages/front_matter_parser.rb
+++ b/lib/gitlab/wiki_pages/front_matter_parser.rb
@@ -105,9 +105,7 @@ def parse_front_matter_block
       end
 
       def strip_front_matter_block
-        Gitlab::FrontMatter::PATTERN_UNTRUSTED_REGEX.replace_gsub(wiki_content) do
-          ''
-        end
+        Gitlab::FrontMatter::PATTERN_UNTRUSTED_REGEX.replace(wiki_content, '')
       end
     end
   end
diff --git a/spec/lib/banzai/filter/front_matter_filter_spec.rb b/spec/lib/banzai/filter/front_matter_filter_spec.rb
index 81da8bb52f802fa119959c8e072a0c5bd8724eb7..72f772d9d96197c0b600726545c5e981e200fe16 100644
--- a/spec/lib/banzai/filter/front_matter_filter_spec.rb
+++ b/spec/lib/banzai/filter/front_matter_filter_spec.rb
@@ -43,6 +43,26 @@
     end
   end
 
+  it "doesn't insert an extra preceding newline when faced with CRLF line endings" do
+    content = <<~MD.gsub("\n", "\r\n")
+      ---
+      foo: :foo_symbol
+      bar: :bar_symbol
+      ---
+
+      # Header
+
+      Content
+    MD
+
+    output = filter(content)
+
+    aggregate_failures do
+      expect(output).not_to include '---'
+      expect(output).to include "```yaml:frontmatter\nfoo: :foo_symbol"
+    end
+  end
+
   it 'converts TOML frontmatter to a fenced code block' do
     content = <<~MD
       +++
diff --git a/spec/lib/gitlab/wiki_pages/front_matter_parser_spec.rb b/spec/lib/gitlab/wiki_pages/front_matter_parser_spec.rb
index eb403b1fc940cb40c1bfa1da058f0b393fa57eef..67b955e473d5bec8f580a0678fe704f3d9d48284 100644
--- a/spec/lib/gitlab/wiki_pages/front_matter_parser_spec.rb
+++ b/spec/lib/gitlab/wiki_pages/front_matter_parser_spec.rb
@@ -9,7 +9,7 @@
   let(:end_divider) { '---' }
 
   let(:with_front_matter) do
-    <<~MD
+    <<~MD.rstrip
     ---
     a: 1
     b: 2
@@ -35,7 +35,7 @@ def have_correct_front_matter
       it do
         is_expected.to have_attributes(
           front_matter: have_correct_front_matter,
-          content: content + "\n",
+          content: content,
           error: be_nil
         )
       end
@@ -53,6 +53,28 @@ def have_correct_front_matter
       end
     end
 
+    context 'the content itself appears to contain frontmatter' do
+      let(:content) do
+        <<~MD.rstrip
+        ---
+        custom: frontmatter
+        ---
+
+        Yay!
+        MD
+      end
+
+      let(:raw_content) { with_front_matter }
+
+      it do
+        is_expected.to have_attributes(
+          front_matter: have_correct_front_matter,
+          content: content,
+          error: be_nil
+        )
+      end
+    end
+
     context 'there is no front_matter' do
       let(:raw_content) { content }
 
@@ -67,7 +89,7 @@ def have_correct_front_matter
       it do
         is_expected.to have_attributes(
           front_matter: have_correct_front_matter,
-          content: content + "\n",
+          content: content,
           reason: be_nil
         )
       end