diff --git a/CHANGELOG b/CHANGELOG
index 1d1c6d26e11..924f9c6204d 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,6 +5,7 @@ v 7.5.0
   - Fix LDAP config lookup for provider 'ldap'
   - Add Atlassian Bamboo CI service (Drew Blessing)
   - Mentioned @user will receive email even if he is not participating in issue or commit
+  - Session API: Use case-insensitive authentication like in UI (Andrey Krivko)
 
 v 7.4.2
   - Fix internal snippet exposing for unauthenticated users
@@ -49,7 +50,7 @@ v 7.4.0
   - Fix ambiguous sha problem with mentioned commit
   - Fixed bug with apostrophe when at mentioning users
   - Add active directory ldap option
-  - Developers can push to wiki repo. Protected branches does not affect wiki repo any more 
+  - Developers can push to wiki repo. Protected branches does not affect wiki repo any more
   - Faster rev list
   - Fix branch removal
 
diff --git a/app/models/user.rb b/app/models/user.rb
index 154cc0f3e16..52e63cde6f9 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -226,6 +226,11 @@ class User < ActiveRecord::Base
       where("lower(name) LIKE :query OR lower(email) LIKE :query OR lower(username) LIKE :query", query: "%#{query.downcase}%")
     end
 
+    def by_login(login)
+      where('lower(username) = :value OR lower(email) = :value',
+            value: login.to_s.downcase).first
+    end
+
     def by_username_or_id(name_or_id)
       where('users.username = ? OR users.id = ?', name_or_id.to_s, name_or_id.to_i).first
     end
diff --git a/lib/gitlab/auth.rb b/lib/gitlab/auth.rb
index ae33c529b93..30509528b8b 100644
--- a/lib/gitlab/auth.rb
+++ b/lib/gitlab/auth.rb
@@ -1,7 +1,7 @@
 module Gitlab
   class Auth
     def find(login, password)
-      user = User.find_by(email: login) || User.find_by(username: login)
+      user = User.by_login(login)
 
       # If no user is found, or it's an LDAP server, try LDAP.
       #   LDAP users are only authenticated via LDAP
diff --git a/spec/lib/gitlab/auth_spec.rb b/spec/lib/gitlab/auth_spec.rb
index 1f3e1a4a3c1..95fc7e16a11 100644
--- a/spec/lib/gitlab/auth_spec.rb
+++ b/spec/lib/gitlab/auth_spec.rb
@@ -10,13 +10,21 @@ describe Gitlab::Auth do
         password: password,
         password_confirmation: password)
     end
-    let(:username) { 'john' }
+    let(:username) { 'John' }     # username isn't lowercase, test this
     let(:password) { 'my-secret' }
 
     it "should find user by valid login/password" do
       expect( gl_auth.find(username, password) ).to eql user
     end
 
+    it 'should find user by valid email/password with case-insensitive email' do
+      expect(gl_auth.find(user.email.upcase, password)).to eql user
+    end
+
+    it 'should find user by valid username/password with case-insensitive username' do
+      expect(gl_auth.find(username.upcase, password)).to eql user
+    end
+
     it "should not find user with invalid password" do
       password = 'wrong'
       expect( gl_auth.find(username, password) ).to_not eql user
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 6ad57b06e06..6d865cfc691 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -287,6 +287,20 @@ describe User do
     end
   end
 
+  describe '.by_login' do
+    let(:username) { 'John' }
+    let!(:user) { create(:user, username: username) }
+
+    it 'should get the correct user' do
+      expect(User.by_login(user.email.upcase)).to eq user
+      expect(User.by_login(user.email)).to eq user
+      expect(User.by_login(username.downcase)).to eq user
+      expect(User.by_login(username)).to eq user
+      expect(User.by_login(nil)).to be_nil
+      expect(User.by_login('')).to be_nil
+    end
+  end
+
   describe 'all_ssh_keys' do
     it { should have_many(:keys).dependent(:destroy) }
 
diff --git a/spec/requests/api/session_spec.rb b/spec/requests/api/session_spec.rb
index 013f425d6ce..57b2e6cbd6a 100644
--- a/spec/requests/api/session_spec.rb
+++ b/spec/requests/api/session_spec.rb
@@ -19,6 +19,32 @@ describe API::API, api: true  do
       end
     end
 
+    context 'when email has case-typo and password is valid' do
+      it 'should return private token' do
+        post api('/session'), email: user.email.upcase, password: '12345678'
+        expect(response.status).to eq 201
+
+        expect(json_response['email']).to eq user.email
+        expect(json_response['private_token']).to eq user.private_token
+        expect(json_response['is_admin']).to eq user.is_admin?
+        expect(json_response['can_create_project']).to eq user.can_create_project?
+        expect(json_response['can_create_group']).to eq user.can_create_group?
+      end
+    end
+
+    context 'when login has case-typo and password is valid' do
+      it 'should return private token' do
+        post api('/session'), login: user.username.upcase, password: '12345678'
+        expect(response.status).to eq 201
+
+        expect(json_response['email']).to eq user.email
+        expect(json_response['private_token']).to eq user.private_token
+        expect(json_response['is_admin']).to eq user.is_admin?
+        expect(json_response['can_create_project']).to eq user.can_create_project?
+        expect(json_response['can_create_group']).to eq user.can_create_group?
+      end
+    end
+
     context "when invalid password" do
       it "should return authentication error" do
         post api("/session"), email: user.email, password: '123'