diff --git a/app/models/concerns/milestoneish.rb b/app/models/concerns/milestoneish.rb
index 710fc1ed647271ef9511595820c0eead4e02b831..7fe55f8402f5ad38f879daaad66da0aac2c132f2 100644
--- a/app/models/concerns/milestoneish.rb
+++ b/app/models/concerns/milestoneish.rb
@@ -86,6 +86,14 @@ module Milestoneish
     false
   end
 
+  def total_issue_time_spent
+    issues.joins(:timelogs).sum(:time_spent)
+  end
+
+  def human_total_issue_time_spent
+    Gitlab::TimeTrackingFormatter.output(total_issue_time_spent)
+  end
+
   private
 
   def count_issues_by_state(user)
diff --git a/app/models/global_milestone.rb b/app/models/global_milestone.rb
index 18af3c41d618ad34601a9c0e2582d784c7ab0886..c0864769314f8de9646c974fc09e10d4102d47f2 100644
--- a/app/models/global_milestone.rb
+++ b/app/models/global_milestone.rb
@@ -152,12 +152,4 @@ class GlobalMilestone
         @milestones.first.start_date
       end
   end
-
-  def total_time_spent
-    issues.joins(:timelogs).sum(:time_spent) + merge_requests.joins(:timelogs).sum(:time_spent)
-  end
-
-  def human_total_time_spent
-    Gitlab::TimeTrackingFormatter.output(total_time_spent)
-  end
 end
diff --git a/app/models/milestone.rb b/app/models/milestone.rb
index fa2dfcb694b7114d9d93e2bc61423e6c2d2632a1..47e6b785c39eea25c0a09754c48f492be406e786 100644
--- a/app/models/milestone.rb
+++ b/app/models/milestone.rb
@@ -213,14 +213,6 @@ class Milestone < ActiveRecord::Base
     project_id.present?
   end
 
-  def total_time_spent
-    issues.joins(:timelogs).sum(:time_spent) + merge_requests.joins(:timelogs).sum(:time_spent)
-  end
-
-  def human_total_time_spent
-    Gitlab::TimeTrackingFormatter.output(total_time_spent)
-  end
-
   private
 
   # Milestone titles must be unique across project milestones and group milestones
diff --git a/app/views/shared/milestones/_sidebar.html.haml b/app/views/shared/milestones/_sidebar.html.haml
index e244adf7d5282e170b780e784ff3291b61029403..d396e80e12c2f3e3d10eb9bc8102b207b38ead20 100644
--- a/app/views/shared/milestones/_sidebar.html.haml
+++ b/app/views/shared/milestones/_sidebar.html.haml
@@ -89,15 +89,15 @@
       .sidebar-collapsed-icon
         = custom_icon('icon_hourglass')
         %span.collapsed-milestone-total-time-spent
-        - if milestone.human_total_time_spent
-          = milestone.human_total_time_spent
+        - if milestone.human_total_issue_time_spent
+          = milestone.human_total_issue_time_spent
         - else
           None
       .title.hide-collapsed
-        Total time spent
+        Total issue time spent
       .value.hide-collapsed
-        - if milestone.human_total_time_spent
-          %span.bold= milestone.human_total_time_spent
+        - if milestone.human_total_issue_time_spent
+          %span.bold= milestone.human_total_issue_time_spent
         - else
           %span.no-value No time spent
 
diff --git a/spec/models/concerns/milestoneish_spec.rb b/spec/models/concerns/milestoneish_spec.rb
index 66353935427df2087e8b2c45dd1b5e1a652fa877..c0a51e170fcf6f34987d562073f86b2ccf3b17cd 100644
--- a/spec/models/concerns/milestoneish_spec.rb
+++ b/spec/models/concerns/milestoneish_spec.rb
@@ -186,4 +186,15 @@ describe Milestone, 'Milestoneish' do
       expect(milestone.elapsed_days).to eq(2)
     end
   end
+
+  describe '#total_issue_time_spent' do
+    it 'calculates total issue time spent' do
+      closed_issue_1.spend_time(duration: 300, user: author)
+      closed_issue_1.save!
+      closed_issue_2.spend_time(duration: 600, user: assignee)
+      closed_issue_2.save!
+
+      expect(milestone.total_issue_time_spent).to eq(900)
+    end
+  end
 end
diff --git a/spec/models/global_milestone_spec.rb b/spec/models/global_milestone_spec.rb
index 4874dcbd58e9e7ea76cb5420d6a05e347622c544..ab58f5c5021a2693879c3b45e9e14fb0e6093159 100644
--- a/spec/models/global_milestone_spec.rb
+++ b/spec/models/global_milestone_spec.rb
@@ -190,37 +190,4 @@ describe GlobalMilestone do
       end
     end
   end
-
-  describe '#total_time_spent' do
-    let(:milestone1_project1) { create(:milestone, title: "Milestone v1.2", project: project1) }
-    let(:milestone1_project2) { create(:milestone, title: "Milestone v1.2", project: project2) }
-    let(:issue1) { create(:issue, milestone: milestone1_project1) }
-    let(:issue2) { create(:issue, milestone: milestone1_project2) }
-    let(:merge_request1) { create(:merge_request, milestone: milestone1_project1) }
-    let(:merge_request2) { create(:merge_request, milestone: milestone1_project2) }
-
-    before do
-      milestones =
-        [
-          milestone1_project1,
-          milestone1_project2
-        ]
-      milestones_relation = Milestone.where(id: milestones.map(&:id))
-
-      @global_milestone = described_class.new(milestone1_project1.title, milestones_relation)
-    end
-
-    it 'calculates total time spent' do
-      issue1.spend_time(duration: 300, user: user)
-      issue1.save!
-      issue2.spend_time(duration: 600, user: user2)
-      issue2.save!
-      merge_request1.spend_time(duration: 200, user: user)
-      merge_request1.save!
-      merge_request2.spend_time(duration: 100, user: user2)
-      merge_request2.save!
-
-      expect(@global_milestone.total_time_spent).to eq(1200)
-    end
-  end
 end
diff --git a/spec/models/milestone_spec.rb b/spec/models/milestone_spec.rb
index 10c24317574747e27df0527110c7dc90ec4234d7..13e37fffa4e34d54fd3205113633866ead6383a5 100644
--- a/spec/models/milestone_spec.rb
+++ b/spec/models/milestone_spec.rb
@@ -284,27 +284,4 @@ describe Milestone do
       expect(milestone.participants).to eq [user]
     end
   end
-
-  describe '#total_time_spent' do
-    let(:user) { build(:user) }
-    let(:project) { build(:project, name: 'sample-project') }
-    let(:milestone) { build(:milestone, iid: 1, project: project) }
-    let(:issue1) { build(:issue, milestone: milestone) }
-    let(:issue2) { build(:issue, milestone: milestone) }
-    let(:merge_request1) { build(:merge_request, milestone: milestone) }
-    let(:merge_request2) { build(:merge_request, milestone: milestone) }
-
-    it 'calculates total time spent' do
-      issue1.spend_time(duration: 300, user: user)
-      issue1.save!
-      issue2.spend_time(duration: 600, user: user)
-      issue2.save!
-      merge_request1.spend_time(duration: 200, user: user)
-      merge_request1.save!
-      merge_request2.spend_time(duration: 100, user: user)
-      merge_request2.save!
-
-      expect(milestone.total_time_spent).to eq(1200)
-    end
-  end
 end