diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index a6b606d13de..bf5f92f8462 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -3,8 +3,8 @@ module Ci
     include TokenAuthenticatable
     include AfterCommitQueue
 
-    belongs_to :runner, class_name: 'Ci::Runner'
-    belongs_to :trigger_request, class_name: 'Ci::TriggerRequest'
+    belongs_to :runner
+    belongs_to :trigger_request
     belongs_to :erased_by, class_name: 'User'
 
     serialize :options
diff --git a/app/models/ci/pipeline.rb b/app/models/ci/pipeline.rb
index d5c1e03b461..adda3b8f40c 100644
--- a/app/models/ci/pipeline.rb
+++ b/app/models/ci/pipeline.rb
@@ -7,12 +7,12 @@ module Ci
 
     self.table_name = 'ci_commits'
 
-    belongs_to :project, class_name: '::Project', foreign_key: :gl_project_id
+    belongs_to :project, foreign_key: :gl_project_id
     belongs_to :user
 
     has_many :statuses, class_name: 'CommitStatus', foreign_key: :commit_id
-    has_many :builds, class_name: 'Ci::Build', foreign_key: :commit_id
-    has_many :trigger_requests, dependent: :destroy, class_name: 'Ci::TriggerRequest', foreign_key: :commit_id
+    has_many :builds, foreign_key: :commit_id
+    has_many :trigger_requests, dependent: :destroy, foreign_key: :commit_id
 
     validates_presence_of :sha, unless: :importing?
     validates_presence_of :ref, unless: :importing?
diff --git a/app/models/ci/runner.rb b/app/models/ci/runner.rb
index 44cb19ece3b..123930273e0 100644
--- a/app/models/ci/runner.rb
+++ b/app/models/ci/runner.rb
@@ -6,9 +6,9 @@ module Ci
     AVAILABLE_SCOPES = %w[specific shared active paused online]
     FORM_EDITABLE = %i[description tag_list active run_untagged locked]
 
-    has_many :builds, class_name: 'Ci::Build'
-    has_many :runner_projects, dependent: :destroy, class_name: 'Ci::RunnerProject'
-    has_many :projects, through: :runner_projects, class_name: '::Project', foreign_key: :gl_project_id
+    has_many :builds
+    has_many :runner_projects, dependent: :destroy
+    has_many :projects, through: :runner_projects, foreign_key: :gl_project_id
 
     has_one :last_build, ->() { order('id DESC') }, class_name: 'Ci::Build'
 
diff --git a/app/models/ci/runner_project.rb b/app/models/ci/runner_project.rb
index 4b44ffa886e..1f9baeca5b1 100644
--- a/app/models/ci/runner_project.rb
+++ b/app/models/ci/runner_project.rb
@@ -2,8 +2,8 @@ module Ci
   class RunnerProject < ActiveRecord::Base
     extend Ci::Model
     
-    belongs_to :runner, class_name: 'Ci::Runner'
-    belongs_to :project, class_name: '::Project', foreign_key: :gl_project_id
+    belongs_to :runner
+    belongs_to :project, foreign_key: :gl_project_id
 
     validates_uniqueness_of :runner_id, scope: :gl_project_id
   end
diff --git a/app/models/ci/trigger.rb b/app/models/ci/trigger.rb
index a0b19b51a12..62889fe80d8 100644
--- a/app/models/ci/trigger.rb
+++ b/app/models/ci/trigger.rb
@@ -4,8 +4,8 @@ module Ci
 
     acts_as_paranoid
 
-    belongs_to :project, class_name: '::Project', foreign_key: :gl_project_id
-    has_many :trigger_requests, dependent: :destroy, class_name: 'Ci::TriggerRequest'
+    belongs_to :project, foreign_key: :gl_project_id
+    has_many :trigger_requests, dependent: :destroy
 
     validates_presence_of :token
     validates_uniqueness_of :token
diff --git a/app/models/ci/trigger_request.rb b/app/models/ci/trigger_request.rb
index fc674871743..2b807731d0d 100644
--- a/app/models/ci/trigger_request.rb
+++ b/app/models/ci/trigger_request.rb
@@ -2,9 +2,9 @@ module Ci
   class TriggerRequest < ActiveRecord::Base
     extend Ci::Model
 
-    belongs_to :trigger, class_name: 'Ci::Trigger'
-    belongs_to :pipeline, class_name: 'Ci::Pipeline', foreign_key: :commit_id
-    has_many :builds, class_name: 'Ci::Build'
+    belongs_to :trigger
+    belongs_to :pipeline, foreign_key: :commit_id
+    has_many :builds
 
     serialize :variables
 
diff --git a/app/models/ci/variable.rb b/app/models/ci/variable.rb
index 6959223aed9..94d9e2b3208 100644
--- a/app/models/ci/variable.rb
+++ b/app/models/ci/variable.rb
@@ -2,7 +2,7 @@ module Ci
   class Variable < ActiveRecord::Base
     extend Ci::Model
 
-    belongs_to :project, class_name: '::Project', foreign_key: :gl_project_id
+    belongs_to :project, foreign_key: :gl_project_id
 
     validates_uniqueness_of :key, scope: :gl_project_id
     validates :key,
diff --git a/app/models/commit_status.rb b/app/models/commit_status.rb
index 7b554be4f9a..4cb3a69416e 100644
--- a/app/models/commit_status.rb
+++ b/app/models/commit_status.rb
@@ -5,7 +5,7 @@ class CommitStatus < ActiveRecord::Base
 
   self.table_name = 'ci_builds'
 
-  belongs_to :project, class_name: '::Project', foreign_key: :gl_project_id
+  belongs_to :project, foreign_key: :gl_project_id
   belongs_to :pipeline, class_name: 'Ci::Pipeline', foreign_key: :commit_id
   belongs_to :user
 
diff --git a/app/models/group.rb b/app/models/group.rb
index 00a595d2705..552e1154df6 100644
--- a/app/models/group.rb
+++ b/app/models/group.rb
@@ -6,7 +6,7 @@ class Group < Namespace
   include AccessRequestable
   include Referable
 
-  has_many :group_members, -> { where(requested_at: nil) }, dependent: :destroy, as: :source, class_name: 'GroupMember'
+  has_many :group_members, -> { where(requested_at: nil) }, dependent: :destroy, as: :source
   alias_method :members, :group_members
   has_many :users, through: :group_members
   has_many :owners,
diff --git a/app/models/members/group_member.rb b/app/models/members/group_member.rb
index 1b54a85d064..204f34f0269 100644
--- a/app/models/members/group_member.rb
+++ b/app/models/members/group_member.rb
@@ -1,7 +1,7 @@
 class GroupMember < Member
   SOURCE_TYPE = 'Namespace'
 
-  belongs_to :group, class_name: 'Group', foreign_key: 'source_id'
+  belongs_to :group, foreign_key: 'source_id'
 
   # Make sure group member points only to group as it source
   default_value_for :source_type, SOURCE_TYPE
diff --git a/app/models/members/project_member.rb b/app/models/members/project_member.rb
index e4880973117..008fff0857c 100644
--- a/app/models/members/project_member.rb
+++ b/app/models/members/project_member.rb
@@ -3,7 +3,7 @@ class ProjectMember < Member
 
   include Gitlab::ShellAdapter
 
-  belongs_to :project, class_name: 'Project', foreign_key: 'source_id'
+  belongs_to :project, foreign_key: 'source_id'
 
   # Make sure project member points only to project as it source
   default_value_for :source_type, SOURCE_TYPE
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index c476a3bb14e..4872f8b8649 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -6,8 +6,8 @@ class MergeRequest < ActiveRecord::Base
   include Taskable
   include Importable
 
-  belongs_to :target_project, foreign_key: :target_project_id, class_name: "Project"
-  belongs_to :source_project, foreign_key: :source_project_id, class_name: "Project"
+  belongs_to :target_project, class_name: "Project"
+  belongs_to :source_project, class_name: "Project"
   belongs_to :merge_user, class_name: "User"
 
   has_many :merge_request_diffs, dependent: :destroy
diff --git a/app/models/project.rb b/app/models/project.rb
index af117f0acb0..fbf7012972e 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -63,11 +63,11 @@ class Project < ActiveRecord::Base
   alias_attribute :title, :name
 
   # Relations
-  belongs_to :creator, foreign_key: 'creator_id', class_name: 'User'
+  belongs_to :creator, class_name: 'User'
   belongs_to :group, -> { where(type: 'Group') }, foreign_key: 'namespace_id'
   belongs_to :namespace
 
-  has_one :last_event, -> {order 'events.created_at DESC'}, class_name: 'Event', foreign_key: 'project_id'
+  has_one :last_event, -> {order 'events.created_at DESC'}, class_name: 'Event'
   has_many :boards, before_add: :validate_board_limit, dependent: :destroy
 
   # Project services
@@ -116,7 +116,7 @@ class Project < ActiveRecord::Base
   has_many :hooks,              dependent: :destroy, class_name: 'ProjectHook'
   has_many :protected_branches, dependent: :destroy
 
-  has_many :project_members, -> { where(requested_at: nil) }, dependent: :destroy, as: :source, class_name: 'ProjectMember'
+  has_many :project_members, -> { where(requested_at: nil) }, dependent: :destroy, as: :source
   alias_method :members, :project_members
   has_many :users, through: :project_members
 
@@ -137,7 +137,7 @@ class Project < ActiveRecord::Base
   has_one :import_data, dependent: :destroy, class_name: "ProjectImportData"
   has_one :project_feature, dependent: :destroy
 
-  has_many :commit_statuses, dependent: :destroy, class_name: 'CommitStatus', foreign_key: :gl_project_id
+  has_many :commit_statuses, dependent: :destroy, foreign_key: :gl_project_id
   has_many :pipelines, dependent: :destroy, class_name: 'Ci::Pipeline', foreign_key: :gl_project_id
   has_many :builds, class_name: 'Ci::Build', foreign_key: :gl_project_id # the builds are created from the commit_statuses
   has_many :runner_projects, dependent: :destroy, class_name: 'Ci::RunnerProject', foreign_key: :gl_project_id
diff --git a/app/models/user.rb b/app/models/user.rb
index f367f4616fb..521879444d4 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -47,7 +47,7 @@ class User < ActiveRecord::Base
   #
 
   # Namespace for personal projects
-  has_one :namespace, -> { where type: nil }, dependent: :destroy, foreign_key: :owner_id, class_name: "Namespace"
+  has_one :namespace, -> { where type: nil }, dependent: :destroy, foreign_key: :owner_id
 
   # Profile
   has_many :keys, dependent: :destroy
@@ -66,17 +66,17 @@ class User < ActiveRecord::Base
   # Projects
   has_many :groups_projects,          through: :groups, source: :projects
   has_many :personal_projects,        through: :namespace, source: :projects
-  has_many :project_members, -> { where(requested_at: nil) }, dependent: :destroy, class_name: 'ProjectMember'
+  has_many :project_members, -> { where(requested_at: nil) }, dependent: :destroy
   has_many :projects,                 through: :project_members
   has_many :created_projects,         foreign_key: :creator_id, class_name: 'Project'
   has_many :users_star_projects, dependent: :destroy
   has_many :starred_projects, through: :users_star_projects, source: :project
 
-  has_many :snippets,                 dependent: :destroy, foreign_key: :author_id, class_name: "Snippet"
+  has_many :snippets,                 dependent: :destroy, foreign_key: :author_id
   has_many :issues,                   dependent: :destroy, foreign_key: :author_id
   has_many :notes,                    dependent: :destroy, foreign_key: :author_id
   has_many :merge_requests,           dependent: :destroy, foreign_key: :author_id
-  has_many :events,                   dependent: :destroy, foreign_key: :author_id,   class_name: "Event"
+  has_many :events,                   dependent: :destroy, foreign_key: :author_id
   has_many :subscriptions,            dependent: :destroy
   has_many :recent_events, -> { order "id DESC" }, foreign_key: :author_id,   class_name: "Event"
   has_many :assigned_issues,          dependent: :destroy, foreign_key: :assignee_id, class_name: "Issue"
diff --git a/spec/models/members/project_member_spec.rb b/spec/models/members/project_member_spec.rb
index b2fe96e2e02..f6b2ec5ae31 100644
--- a/spec/models/members/project_member_spec.rb
+++ b/spec/models/members/project_member_spec.rb
@@ -2,7 +2,7 @@ require 'spec_helper'
 
 describe ProjectMember, models: true do
   describe 'associations' do
-    it { is_expected.to belong_to(:project).class_name('Project').with_foreign_key(:source_id) }
+    it { is_expected.to belong_to(:project).with_foreign_key(:source_id) }
   end
 
   describe 'validations' do
diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb
index 6e5137602aa..3155eff9ee1 100644
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
@@ -6,8 +6,8 @@ describe MergeRequest, models: true do
   subject { create(:merge_request) }
 
   describe 'associations' do
-    it { is_expected.to belong_to(:target_project).with_foreign_key(:target_project_id).class_name('Project') }
-    it { is_expected.to belong_to(:source_project).with_foreign_key(:source_project_id).class_name('Project') }
+    it { is_expected.to belong_to(:target_project).class_name('Project') }
+    it { is_expected.to belong_to(:source_project).class_name('Project') }
     it { is_expected.to belong_to(:merge_user).class_name("User") }
     it { is_expected.to have_many(:merge_request_diffs).dependent(:destroy) }
   end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 65b2896930a..10c39b90212 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -15,11 +15,11 @@ describe User, models: true do
 
   describe 'associations' do
     it { is_expected.to have_one(:namespace) }
-    it { is_expected.to have_many(:snippets).class_name('Snippet').dependent(:destroy) }
+    it { is_expected.to have_many(:snippets).dependent(:destroy) }
     it { is_expected.to have_many(:project_members).dependent(:destroy) }
     it { is_expected.to have_many(:groups) }
     it { is_expected.to have_many(:keys).dependent(:destroy) }
-    it { is_expected.to have_many(:events).class_name('Event').dependent(:destroy) }
+    it { is_expected.to have_many(:events).dependent(:destroy) }
     it { is_expected.to have_many(:recent_events).class_name('Event') }
     it { is_expected.to have_many(:issues).dependent(:destroy) }
     it { is_expected.to have_many(:notes).dependent(:destroy) }