diff --git a/CHANGELOG b/CHANGELOG
index a98bdd26f74..658ed5aef72 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -16,6 +16,7 @@ v 8.6.0 (unreleased)
   - Update documentation to reflect Guest role not being enforced on internal projects
   - Allow search for logged out users
   - Don't show Issues/MRs from archived projects in Groups view
+  - Fix wrong "iid of max iid" in Issuable sidebar for some merged MRs
   - Increase the notes polling timeout over time (Roberto Dip)
   - Show labels in dashboard and group milestone views
   - Add main language of a project in the list of projects (Tiago Botelho)
diff --git a/app/helpers/issuables_helper.rb b/app/helpers/issuables_helper.rb
index 91a3aa371ef..2dfeddf7368 100644
--- a/app/helpers/issuables_helper.rb
+++ b/app/helpers/issuables_helper.rb
@@ -31,7 +31,11 @@ module IssuablesHelper
   end
 
   def issuable_state_scope(issuable)
-    issuable.open? ? :opened : :closed
+    if issuable.respond_to?(:merged?) && issuable.merged?
+      :merged
+    else
+      issuable.open? ? :opened : :closed
+    end
   end
 
 end
diff --git a/features/project/merge_requests.feature b/features/project/merge_requests.feature
index f8d9fe1854d..74685d24a7d 100644
--- a/features/project/merge_requests.feature
+++ b/features/project/merge_requests.feature
@@ -46,11 +46,18 @@ Feature: Project Merge Requests
     Then I should see "Feature NS-03" in merge requests
     And I should see "Bug NS-04" in merge requests
 
-  Scenario: I visit merge request page
+  Scenario: I visit an open merge request page
     Given I click link "Bug NS-04"
     Then I should see merge request "Bug NS-04"
     And I should see "1 of 1" in the sidebar
 
+  Scenario: I visit a merged merge request page
+    Given project "Shop" have "Feature NS-05" merged merge request
+    And I click link "Merged"
+    And I click link "Feature NS-05"
+    Then I should see merge request "Feature NS-05"
+    And I should see "3 of 3" in the sidebar
+
   Scenario: I close merge request page
     Given I click link "Bug NS-04"
     And I click link "Close"
diff --git a/features/steps/project/merge_requests.rb b/features/steps/project/merge_requests.rb
index c19b15bc9ed..2eb98e91dbf 100644
--- a/features/steps/project/merge_requests.rb
+++ b/features/steps/project/merge_requests.rb
@@ -16,10 +16,18 @@ class Spinach::Features::ProjectMergeRequests < Spinach::FeatureSteps
     click_link "Bug NS-04"
   end
 
+  step 'I click link "Feature NS-05"' do
+    click_link "Feature NS-05"
+  end
+
   step 'I click link "All"' do
     click_link "All"
   end
 
+  step 'I click link "Merged"' do
+    click_link "Merged"
+  end
+
   step 'I click link "Closed"' do
     click_link "Closed"
   end
@@ -40,6 +48,10 @@ class Spinach::Features::ProjectMergeRequests < Spinach::FeatureSteps
     expect(page).to have_content "Bug NS-04"
   end
 
+  step 'I should see merge request "Feature NS-05"' do
+    expect(page).to have_content "Feature NS-05"
+  end
+
   step 'I should not see "master" branch' do
     expect(find('.merge-request-info')).not_to have_content "master"
   end
@@ -120,6 +132,14 @@ class Spinach::Features::ProjectMergeRequests < Spinach::FeatureSteps
            author: project.users.first)
   end
 
+  step 'project "Shop" have "Feature NS-05" merged merge request' do
+    create(:merged_merge_request,
+           title: "Feature NS-05",
+           source_project: project,
+           target_project: project,
+           author: project.users.first)
+  end
+
   step 'project "Shop" have "Bug NS-07" open merge request with rebased branch' do
     create(:merge_request, :rebased,
       title: "Bug NS-07",
diff --git a/features/steps/shared/issuable.rb b/features/steps/shared/issuable.rb
index ae10c6069a9..7c094bab8aa 100644
--- a/features/steps/shared/issuable.rb
+++ b/features/steps/shared/issuable.rb
@@ -147,6 +147,10 @@ module SharedIssuable
     expect_sidebar_content('2 of 2')
   end
 
+  step 'I should see "3 of 3" in the sidebar' do
+    expect_sidebar_content('3 of 3')
+  end
+
   step 'I click link "Next" in the sidebar' do
     page.within '.issuable-sidebar' do
       click_link 'Next'
diff --git a/spec/factories/merge_requests.rb b/spec/factories/merge_requests.rb
index ca1c636fce4..a9df5fa1d3a 100644
--- a/spec/factories/merge_requests.rb
+++ b/spec/factories/merge_requests.rb
@@ -56,6 +56,10 @@ FactoryGirl.define do
       target_branch "feature"
     end
 
+    trait :merged do
+      state :merged
+    end
+
     trait :closed do
       state :closed
     end
@@ -84,6 +88,7 @@ FactoryGirl.define do
       merge_user author
     end
 
+    factory :merged_merge_request, traits: [:merged]
     factory :closed_merge_request, traits: [:closed]
     factory :reopened_merge_request, traits: [:reopened]
     factory :merge_request_with_diffs, traits: [:with_diffs]