diff --git a/CHANGELOG b/CHANGELOG
index 27c595585a964f93d1bf202df70c0b1389a45d3b..a5364178bab20a2a69615204aee213d14314eded 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -31,6 +31,7 @@ v 8.6.0 (unreleased)
   - Allow to define on which builds the current one depends on
   - Fix bug where Bitbucket `closed` issues were imported as `opened` (Iuri de Silvio)
   - 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)
   - Add shortcut to toggle markdown preview (Florent Baldino)
   - Show labels in dashboard and group milestone views
diff --git a/app/helpers/issuables_helper.rb b/app/helpers/issuables_helper.rb
index 91a3aa371ef541042d35c18a926d1151bd8408ae..2dfeddf7368684c23b47e716d1ee5abd872d638b 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 f8d9fe1854dbbe3872e9e3718911d5ee2e8cb6dd..74685d24a7d86aabd24adab183907a76782383e0 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 df4259b9ddf2d79a03c8038fb0fc6e02be94aebd..91fe19dd477f36ae55cd7107bbde82e74a0331c7 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 e59bfbea9982dce78ac03a3cfdef1b2bce21a7cf..b6d70a26c2163076823223c2c454b40cb725ef92 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 ca1c636fce4bcdbd385ea59954d16519a0e0f299..a9df5fa1d3a8572cdfc6debdd25d9a112f0bc2da 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]