diff --git a/changelogs/unreleased/fix-api-deprecation.yml b/changelogs/unreleased/fix-api-deprecation.yml
new file mode 100644
index 0000000000000000000000000000000000000000..90285ddf058935e31147f01b10b1b12c347e1508
--- /dev/null
+++ b/changelogs/unreleased/fix-api-deprecation.yml
@@ -0,0 +1,4 @@
+---
+title: Fix a Grape deprecation, use `#request_method` instead of `#route_method`
+merge_request:
+author:
diff --git a/lib/api/helpers.rb b/lib/api/helpers.rb
index fe00c83bff3d71a633e714009e4d40191ea6c05a..ee9247ee240566a86944ae7e3ea37eafe889199b 100644
--- a/lib/api/helpers.rb
+++ b/lib/api/helpers.rb
@@ -96,7 +96,7 @@ module API
     end
 
     def authenticate_non_get!
-      authenticate! unless %w[GET HEAD].include?(route.route_method)
+      authenticate! unless %w[GET HEAD].include?(route.request_method)
     end
 
     def authenticate_by_gitlab_shell_token!
diff --git a/spec/requests/api/helpers_spec.rb b/spec/requests/api/helpers_spec.rb
index c3d7ac3eef8407ce4a1dd34124bf555bb51181f7..b8ee2293a335f08bfbbfcb999018cb6d95da6856 100644
--- a/spec/requests/api/helpers_spec.rb
+++ b/spec/requests/api/helpers_spec.rb
@@ -396,7 +396,7 @@ describe API::Helpers, api: true do
     %w[HEAD GET].each do |method_name|
       context "method is #{method_name}" do
         before do
-          expect_any_instance_of(self.class).to receive(:route).and_return(double(route_method: method_name))
+          expect_any_instance_of(self.class).to receive(:route).and_return(double(request_method: method_name))
         end
 
         it 'does not raise an error' do
@@ -410,7 +410,7 @@ describe API::Helpers, api: true do
     %w[POST PUT PATCH DELETE].each do |method_name|
       context "method is #{method_name}" do
         before do
-          expect_any_instance_of(self.class).to receive(:route).and_return(double(route_method: method_name))
+          expect_any_instance_of(self.class).to receive(:route).and_return(double(request_method: method_name))
         end
 
         it 'calls authenticate!' do