diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 128628a57..f0b184338 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -56,6 +56,9 @@ jobs:
           - ruby: '4.0'
             gemfile: gemfiles/multi_xml.gemfile
             specs: 'spec/integration/multi_xml'
+          - ruby: '4.0'
+            gemfile: gemfiles/multi_xml_0_8.gemfile
+            specs: 'spec/integration/multi_xml'
     runs-on: ubuntu-latest
     env:
       BUNDLE_GEMFILE: ${{ github.workspace }}/${{ matrix.gemfile }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc43a3883..94f80a54e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -76,6 +76,7 @@
 * [#2706](https://github.com/ruby-grape/grape/pull/2706): Fix `optional :foo, message: 'oops'` raising `UnknownValidator` - [@ericproulx](https://github.com/ericproulx).
 * [#2751](https://github.com/ruby-grape/grape/pull/2751): Fix structured error messages leaking the raw i18n key for an undefined optional step such as `summary` (closes #2748) - [@ericproulx](https://github.com/ericproulx).
 * [#2759](https://github.com/ruby-grape/grape/pull/2759): Use `create_additions: false` in `Grape::Json.load` to prevent object instantiation via the `json_class` key when using the stdlib JSON fallback - [@dblock](https://github.com/dblock).
+* [#2765](https://github.com/ruby-grape/grape/pull/2765): Detect the `MultiXML` constant to avoid the multi_xml 0.9 `MultiXml` deprecation - [@ericproulx](https://github.com/ericproulx).
 * [#2764](https://github.com/ruby-grape/grape/pull/2764): Route `Grape::Json` through the non-deprecated `MultiJSON` API - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
diff --git a/gemfiles/multi_xml.gemfile b/gemfiles/multi_xml.gemfile
index 3cd7774f9..8e1a50374 100644
--- a/gemfiles/multi_xml.gemfile
+++ b/gemfiles/multi_xml.gemfile
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
-gem 'multi_xml'
+gem 'multi_xml', '>= 0.9'
 
 eval_gemfile '../Gemfile'
diff --git a/gemfiles/multi_xml_0_8.gemfile b/gemfiles/multi_xml_0_8.gemfile
new file mode 100644
index 000000000..598a74e78
--- /dev/null
+++ b/gemfiles/multi_xml_0_8.gemfile
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+gem 'multi_xml', '< 0.9'
+
+eval_gemfile '../Gemfile'
diff --git a/lib/grape/xml.rb b/lib/grape/xml.rb
index 85287814a..9b6872808 100644
--- a/lib/grape/xml.rb
+++ b/lib/grape/xml.rb
@@ -1,7 +1,14 @@
 # frozen_string_literal: true
 
 module Grape
-  if defined?(::MultiXml)
+  # Since multi_xml 0.9.0 the canonical constant is MultiXML; MultiXml is a
+  # deprecated alias (removed in v1.0) that warns on use. Prefer MultiXML so
+  # Grape::Xml.parse doesn't trip the deprecation, falling back to the legacy
+  # constant and then ActiveSupport::XmlMini.
+  # https://github.com/sferik/multi_xml/blob/v0.9.1/CHANGELOG.md
+  if defined?(::MultiXML)
+    Xml = ::MultiXML
+  elsif defined?(::MultiXml)
     Xml = ::MultiXml
   else
     Xml = ::ActiveSupport::XmlMini
diff --git a/spec/integration/multi_xml/xml_spec.rb b/spec/integration/multi_xml/xml_spec.rb
index a5d998847..740916e76 100644
--- a/spec/integration/multi_xml/xml_spec.rb
+++ b/spec/integration/multi_xml/xml_spec.rb
@@ -1,7 +1,23 @@
 # frozen_string_literal: true
 
 describe Grape::Xml, if: defined?(MultiXml) do
-  subject { described_class }
+  # Exercise the full request stack: a Grape API parses an XML body through the
+  # active multi_xml backend (MultiXML on >= 0.9, the legacy MultiXml alias on
+  # < 0.9). Calling parse through the deprecated MultiXml constant would raise
+  # via the suite's deprecation handler (see spec/support/deprecated_warning_handlers.rb).
+  let(:app) do
+    Class.new(Grape::API) do
+      post '/request_body' do
+        params[:user]
+      end
+    end
+  end
 
-  it { is_expected.to eq(MultiXml) }
+  it 'parses an XML request body into params' do
+    env = Rack::MockRequest.env_for('/request_body', method: Rack::POST, input: '<user>Bobby T.</user>', 'CONTENT_TYPE' => 'application/xml')
+    response = Rack::MockResponse[*app.call(env)]
+
+    expect(response.status).to eq(201)
+    expect(response.body).to eq('Bobby T.')
+  end
 end