diff --git a/changelogs/unreleased/42231-protected-branches-api-route-returns-404-for-branches-with-dots.yml b/changelogs/unreleased/42231-protected-branches-api-route-returns-404-for-branches-with-dots.yml
new file mode 100644
index 00000000000..fbc589ea53d
--- /dev/null
+++ b/changelogs/unreleased/42231-protected-branches-api-route-returns-404-for-branches-with-dots.yml
@@ -0,0 +1,5 @@
+---
+title: Fix protected branches API to accept name parameter with dot
+merge_request:
+author:
+type: fixed
diff --git a/lib/api/protected_branches.rb b/lib/api/protected_branches.rb
index 614822509f0..c15c487deb4 100644
--- a/lib/api/protected_branches.rb
+++ b/lib/api/protected_branches.rb
@@ -2,7 +2,7 @@ module API
   class ProtectedBranches < Grape::API
     include PaginationParams
 
-    BRANCH_ENDPOINT_REQUIREMENTS = API::PROJECT_ENDPOINT_REQUIREMENTS.merge(branch: API::NO_SLASH_URL_PART_REGEX)
+    BRANCH_ENDPOINT_REQUIREMENTS = API::PROJECT_ENDPOINT_REQUIREMENTS.merge(name: API::NO_SLASH_URL_PART_REGEX)
 
     before { authorize_admin_project }
 
diff --git a/spec/requests/api/protected_branches_spec.rb b/spec/requests/api/protected_branches_spec.rb
index 10e6a3c07c8..1d23e023bb6 100644
--- a/spec/requests/api/protected_branches_spec.rb
+++ b/spec/requests/api/protected_branches_spec.rb
@@ -80,6 +80,12 @@ describe API::ProtectedBranches do
 
         it_behaves_like 'protected branch'
       end
+
+      context 'when protected branch contains a period' do
+        let(:protected_name) { 'my.feature' }
+
+        it_behaves_like 'protected branch'
+      end
     end
 
     context 'when authenticated as a guest' do