diff --git a/test/unit/active_model/serializer/has_many_test.rb b/test/unit/active_model/serializer/has_many_test.rb
index 77e27875..541df46b 100644
--- a/test/unit/active_model/serializer/has_many_test.rb
+++ b/test/unit/active_model/serializer/has_many_test.rb
@@ -6,7 +6,7 @@ module ActiveModel
       def setup
         @association = PostSerializer._associations[:comments]
         @old_association = @association.dup
-        @association.embed = :ids
+
         @post = Post.new({ title: 'Title 1', body: 'Body 1', date: '1/1/2000' })
         @post_serializer = PostSerializer.new(@post)
       end
@@ -22,19 +22,25 @@ module ActiveModel
       end
 
       def test_associations_embedding_ids_serialization_using_serializable_hash
+        @association.embed = :ids
+
         assert_equal({
           title: 'Title 1', body: 'Body 1', 'comment_ids' => @post.comments.map { |c| c.object_id }
         }, @post_serializer.serializable_hash)
       end
 
       def test_associations_embedding_ids_serialization_using_as_json
+        @association.embed = :ids
+
         assert_equal({
           'post' => { title: 'Title 1', body: 'Body 1', 'comment_ids' => @post.comments.map { |c| c.object_id } }
         }, @post_serializer.as_json)
       end
 
       def test_associations_embedding_ids_serialization_using_serializable_hash_and_key_from_options
+        @association.embed = :ids
         @association.key = 'key'
+
         assert_equal({
           title: 'Title 1', body: 'Body 1', 'key' => @post.comments.map { |c| c.object_id }
         }, @post_serializer.serializable_hash)
@@ -42,6 +48,7 @@ module ActiveModel
 
       def test_associations_embedding_objects_serialization_using_serializable_hash
         @association.embed = :objects
+
         assert_equal({
           title: 'Title 1', body: 'Body 1', comments: [{ content: 'C1' }, { content: 'C2' }]
         }, @post_serializer.serializable_hash)
@@ -49,6 +56,7 @@ module ActiveModel
 
       def test_associations_embedding_objects_serialization_using_as_json
         @association.embed = :objects
+
         assert_equal({
           'post' => { title: 'Title 1', body: 'Body 1', comments: [{ content: 'C1' }, { content: 'C2' }] }
         }, @post_serializer.as_json)
@@ -70,47 +78,43 @@ module ActiveModel
       def test_associations_embedding_objects_serialization_using_serializable_hash_and_root_from_options
         @association.embed = :objects
         @association.embedded_key = 'root'
+
         assert_equal({
           title: 'Title 1', body: 'Body 1', 'root' => [{ content: 'C1' }, { content: 'C2' }]
         }, @post_serializer.serializable_hash)
       end
 
       def test_associations_embedding_ids_including_objects_serialization_using_serializable_hash
+        @association.embed = :ids
         @association.embed_in_root = true
+
         assert_equal({
           title: 'Title 1', body: 'Body 1', 'comment_ids' => @post.comments.map { |c| c.object_id }
         }, @post_serializer.serializable_hash)
       end
 
       def test_associations_embedding_ids_including_objects_serialization_using_as_json
-        CONFIG.embed = :ids
-        CONFIG.include = true
-
-        @association.send :initialize, @association.name, @association.options
+        @association.embed = :ids
+        @association.embed_in_root = true
 
         assert_equal({
           'post' => { title: 'Title 1', body: 'Body 1', 'comment_ids' => @post.comments.map { |c| c.object_id } },
-          'comments' => [{ content: 'C1' }, { content: 'C2' }]
+          comments: [{ content: 'C1' }, { content: 'C2' }]
         }, @post_serializer.as_json)
-      ensure
-        CONFIG.clear
       end
 
       def test_associations_embedding_nothing_including_objects_serialization_using_as_json
-        CONFIG.embed = nil
-        CONFIG.include = true
-
-        @association.send :initialize, @association.name, @association.options
+        @association.embed = nil
+        @association.embed_in_root = true
 
         assert_equal({
           'post' => { title: 'Title 1', body: 'Body 1' },
-          'comments' => [{ content: 'C1' }, { content: 'C2' }]
+          comments: [{ content: 'C1' }, { content: 'C2' }]
         }, @post_serializer.as_json)
-      ensure
-        CONFIG.clear
       end
 
       def test_associations_using_a_given_serializer
+        @association.embed = :ids
         @association.embed_in_root = true
         @association.serializer_class = Class.new(ActiveModel::Serializer) do
           def content
diff --git a/test/unit/active_model/serializer/has_one_test.rb b/test/unit/active_model/serializer/has_one_test.rb
index 3450cbf0..3dd72693 100644
--- a/test/unit/active_model/serializer/has_one_test.rb
+++ b/test/unit/active_model/serializer/has_one_test.rb
@@ -6,7 +6,7 @@ module ActiveModel
       def setup
         @association = UserSerializer._associations[:profile]
         @old_association = @association.dup
-        @association.embed = :ids
+
         @user = User.new({ name: 'Name 1', email: 'mail@server.com', gender: 'M' })
         @user_serializer = UserSerializer.new(@user)
       end
@@ -22,19 +22,25 @@ module ActiveModel
       end
 
       def test_associations_embedding_ids_serialization_using_serializable_hash
+        @association.embed = :ids
+
         assert_equal({
           name: 'Name 1', email: 'mail@server.com', 'profile_id' => @user.profile.object_id
         }, @user_serializer.serializable_hash)
       end
 
       def test_associations_embedding_ids_serialization_using_as_json
+        @association.embed = :ids
+
         assert_equal({
           'user' => { name: 'Name 1', email: 'mail@server.com', 'profile_id' => @user.profile.object_id }
         }, @user_serializer.as_json)
       end
 
       def test_associations_embedding_ids_serialization_using_serializable_hash_and_key_from_options
+        @association.embed = :ids
         @association.key = 'key'
+
         assert_equal({
           name: 'Name 1', email: 'mail@server.com', 'key' => @user.profile.object_id
         }, @user_serializer.serializable_hash)
@@ -42,6 +48,7 @@ module ActiveModel
 
       def test_associations_embedding_objects_serialization_using_serializable_hash
         @association.embed = :objects
+
         assert_equal({
           name: 'Name 1', email: 'mail@server.com', profile: { name: 'N1', description: 'D1' }
         }, @user_serializer.serializable_hash)
@@ -49,12 +56,14 @@ module ActiveModel
 
       def test_associations_embedding_objects_serialization_using_as_json
         @association.embed = :objects
+
         assert_equal({
           'user' => { name: 'Name 1', email: 'mail@server.com', profile: { name: 'N1', description: 'D1' } }
         }, @user_serializer.as_json)
       end
 
       def test_associations_embedding_nil_ids_serialization_using_as_json
+        @association.embed = :ids
         @user.instance_eval do
           def profile
             nil
@@ -82,22 +91,25 @@ module ActiveModel
       def test_associations_embedding_objects_serialization_using_serializable_hash_and_root_from_options
         @association.embed = :objects
         @association.embedded_key = 'root'
+
         assert_equal({
           name: 'Name 1', email: 'mail@server.com', 'root' => { name: 'N1', description: 'D1' }
         }, @user_serializer.serializable_hash)
       end
 
       def test_associations_embedding_ids_including_objects_serialization_using_serializable_hash
+        @association.embed = :ids
         @association.embed_in_root = true
-        @user_serializer.root = nil
+
         assert_equal({
           name: 'Name 1', email: 'mail@server.com', 'profile_id' => @user.profile.object_id
         }, @user_serializer.serializable_hash)
       end
 
       def test_associations_embedding_ids_including_objects_serialization_using_as_json
+        @association.embed = :ids
         @association.embed_in_root = true
-        @user_serializer.root = nil
+
         assert_equal({
           'user' => { name: 'Name 1', email: 'mail@server.com', 'profile_id' => @user.profile.object_id },
           profile: { name: 'N1', description: 'D1' }
@@ -105,8 +117,8 @@ module ActiveModel
       end
 
       def test_associations_using_a_given_serializer
+        @association.embed = :ids
         @association.embed_in_root = true
-        @user_serializer.root = nil
         @association.serializer_class = Class.new(ActiveModel::Serializer) do
           def name
             'fake'