diff --git a/CHANGELOG b/CHANGELOG
index 4e7af8db8c5..b94d3b79914 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -6,6 +6,7 @@ v 8.11.0 (unreleased)
   - Fix rename `add_users_into_project` and `projects_ids`. !20512 (herminiotorres)
   - Fix the title of the toggle dropdown button. !5515 (herminiotorres)
   - Improve diff performance by eliminating redundant checks for text blobs
+  - Ensure that branch names containing escapable characters (e.g. %20) aren't unescaped indiscriminately. !5770 (ewiltshi)
   - Convert switch icon into icon font (ClemMakesApps)
   - API: Endpoints for enabling and disabling deploy keys
   - API: List access requests, request access, approve, and deny access requests to a project or a group. !4833
diff --git a/lib/extracts_path.rb b/lib/extracts_path.rb
index 51e46da82cc..84688f6646e 100644
--- a/lib/extracts_path.rb
+++ b/lib/extracts_path.rb
@@ -94,7 +94,7 @@ module ExtractsPath
     @options = params.select {|key, value| allowed_options.include?(key) && !value.blank? }
     @options = HashWithIndifferentAccess.new(@options)
 
-    @id = Addressable::URI.unescape(get_id)
+    @id = Addressable::URI.normalize_component(get_id)
     @ref, @path = extract_ref(@id)
     @repo = @project.repository
     if @options[:extended_sha1].blank?
diff --git a/spec/lib/extracts_path_spec.rb b/spec/lib/extracts_path_spec.rb
index b12a7b98d4d..36c77206a3f 100644
--- a/spec/lib/extracts_path_spec.rb
+++ b/spec/lib/extracts_path_spec.rb
@@ -30,15 +30,28 @@ describe ExtractsPath, lib: true do
       expect(@logs_path).to eq("/#{@project.path_with_namespace}/refs/#{ref}/logs_tree/files/ruby/popen.rb")
     end
 
-    context 'escaped sequences in ref' do
-      let(:ref) { "improve%2Fawesome" }
+    context 'escaped slash character in ref' do
+      let(:ref) { 'improve%2Fawesome' }
 
-      it "id has no escape sequences" do
+      it 'has no escape sequences in @ref or @logs_path' do
         assign_ref_vars
+
         expect(@ref).to eq('improve/awesome')
         expect(@logs_path).to eq("/#{@project.path_with_namespace}/refs/#{ref}/logs_tree/files/ruby/popen.rb")
       end
     end
+
+    context 'ref contains %20' do
+      let(:ref) { 'foo%20bar' }
+
+      it 'is not converted to a space in @id' do
+        @project.repository.add_branch(@project.owner, 'foo%20bar', 'master')
+
+        assign_ref_vars
+
+        expect(@id).to start_with('foo%20bar/')
+      end
+    end
   end
 
   describe '#extract_ref' do