diff --git a/tests/fixtures/plugins/database/tester/models/Author.php b/tests/fixtures/plugins/database/tester/models/Author.php
index d323bcd03..f2209551d 100644
--- a/tests/fixtures/plugins/database/tester/models/Author.php
+++ b/tests/fixtures/plugins/database/tester/models/Author.php
@@ -22,4 +22,11 @@ class Author extends Model
         'posts' => 'Database\Tester\Models\Post',
     ];
 
+    /**
+     * @var array Relations
+     */
+    public $hasOne = [
+        'phone' => 'Database\Tester\Models\Phone',
+    ];
+
 }
\ No newline at end of file
diff --git a/tests/fixtures/plugins/database/tester/models/Phone.php b/tests/fixtures/plugins/database/tester/models/Phone.php
new file mode 100644
index 000000000..f123e96ef
--- /dev/null
+++ b/tests/fixtures/plugins/database/tester/models/Phone.php
@@ -0,0 +1,30 @@
+<?php namespace Database\Tester\Models;
+
+use Model;
+
+class Phone extends Model
+{
+
+    /**
+     * @var string The database table used by the model.
+     */
+    public $table = 'database_tester_phones';
+
+    /**
+     * @var array Guarded fields
+     */
+    protected $guarded = ['*'];
+
+    /**
+     * @var array Fillable fields
+     */
+    protected $fillable = [];
+
+    /**
+     * @var array Relations
+     */
+    public $belongsTo = [
+        'author' => 'Database\Tester\Models\Author',
+    ];
+
+}
\ No newline at end of file
diff --git a/tests/fixtures/plugins/database/tester/updates/create_phones_table.php b/tests/fixtures/plugins/database/tester/updates/create_phones_table.php
new file mode 100644
index 000000000..5af8ef778
--- /dev/null
+++ b/tests/fixtures/plugins/database/tester/updates/create_phones_table.php
@@ -0,0 +1,26 @@
+<?php namespace Database\Tester\Updates;
+
+use Schema;
+use October\Rain\Database\Updates\Migration;
+
+class CreatePhonesTable extends Migration
+{
+
+    public function up()
+    {
+        Schema::create('database_tester_phones', function($table)
+        {
+            $table->engine = 'InnoDB';
+            $table->increments('id');
+            $table->string('number')->nullable();
+            $table->integer('author_id')->unsigned()->index()->nullable();
+            $table->timestamps();
+        });
+    }
+
+    public function down()
+    {
+        Schema::dropIfExists('database_tester_phones');
+    }
+
+}
diff --git a/tests/fixtures/plugins/database/tester/updates/version.yaml b/tests/fixtures/plugins/database/tester/updates/version.yaml
index 2fc4b2813..308c088b5 100644
--- a/tests/fixtures/plugins/database/tester/updates/version.yaml
+++ b/tests/fixtures/plugins/database/tester/updates/version.yaml
@@ -3,4 +3,5 @@
     - Create tables
     - create_posts_table.php
     - create_authors_table.php
+    - create_phones_table.php
     - create_categories_table.php
diff --git a/tests/unit/plugins/database/BelongsToModelTest.php b/tests/unit/plugins/database/BelongsToModelTest.php
index fb7d95ed8..acf95f148 100644
--- a/tests/unit/plugins/database/BelongsToModelTest.php
+++ b/tests/unit/plugins/database/BelongsToModelTest.php
@@ -47,6 +47,16 @@ class BelongsToModelTest extends PluginTestCase
         $this->assertEquals($author3->id, $post->author_id);
     }
 
+    public function testGetRelationValue()
+    {
+        Model::unguard();
+        $author = Author::create(['name' => 'Stevie']);
+        $post = Post::make(['title' => "First post", 'author_id' => $author->id]);
+        Model::reguard();
+
+        $this->assertEquals($author->id, $post->getRelationValue('author'));
+    }
+
     public function testDeferredBinding()
     {
         $sessionKey = uniqid('session_key', true);
@@ -87,4 +97,5 @@ class BelongsToModelTest extends PluginTestCase
         $this->assertNull($post->author);
     }
 
+
 }
\ No newline at end of file
diff --git a/tests/unit/plugins/database/HasOneModelTest.php b/tests/unit/plugins/database/HasOneModelTest.php
new file mode 100644
index 000000000..f1cb34b45
--- /dev/null
+++ b/tests/unit/plugins/database/HasOneModelTest.php
@@ -0,0 +1,107 @@
+<?php
+
+use Database\Tester\Models\Author;
+use Database\Tester\Models\Phone;
+
+class HasOneModelTest extends PluginTestCase
+{
+    public function setUp()
+    {
+        parent::setUp();
+
+        include_once base_path().'/tests/fixtures/plugins/database/tester/models/Author.php';
+        include_once base_path().'/tests/fixtures/plugins/database/tester/models/Phone.php';
+
+        $this->runPluginRefreshCommand('Database.Tester');
+    }
+
+    public function testSetRelationValue()
+    {
+        Model::unguard();
+        $author = Author::create(['name' => 'Stevie', 'email' => 'stevie@email.tld']);
+        $phone1 = Phone::create(['number' => '0404040404']);
+        $phone2 = Phone::create(['number' => '0505050505']);
+        $phone3 = Phone::make(['number' => '0606060606']);
+        Model::reguard();
+
+        // Set by Model object
+        $author->phone = $phone1;
+        $author->save();
+        $this->assertEquals($author->id, $phone1->author_id);
+        $this->assertEquals('0404040404', $author->phone->number);
+
+        // Set by primary key
+        $phoneId = $phone2->id;
+        $author->phone = $phoneId;
+        $author->save();
+        $phone2 = Phone::find($phoneId);
+        $this->assertEquals($author->id, $phone2->author_id);
+        $this->assertEquals('0505050505', $author->phone->number);
+
+        // Nullify
+        $author->phone = null;
+        $author->save();
+        $phone2 = Phone::find($phoneId);
+        $this->assertNull($phone2->author_id);
+        $this->assertNull($phone2->author);
+
+        // Deferred in memory
+        $author->phone = $phone3;
+        $this->assertEquals('0606060606', $author->phone->number);
+        $this->assertEquals($author->id, $phone3->author_id);
+    }
+
+    public function testGetRelationValue()
+    {
+        Model::unguard();
+        $author = Author::create(['name' => 'Stevie']);
+        $phone = Phone::create(['number' => '0404040404', 'author_id' => $author->id]);
+        Model::reguard();
+
+        $this->assertEquals($phone->id, $author->getRelationValue('phone'));
+    }
+
+    public function testDeferredBinding()
+    {
+        $sessionKey = uniqid('session_key', true);
+
+        Model::unguard();
+        $author = Author::create(['name' => 'Stevie']);
+        $phone = Phone::create(['number' => '0404040404']);
+        Model::reguard();
+
+        $phoneId = $phone->id;
+
+        // Deferred add
+        $author->phone()->add($phone, $sessionKey);
+        $this->assertNull($phone->author_id);
+        $this->assertNull($author->phone);
+
+        $this->assertEquals(0, $author->phone()->count());
+        $this->assertEquals(1, $author->phone()->withDeferred($sessionKey)->count());
+
+        // Commit deferred
+        $author->save(null, $sessionKey);
+        $phone = Phone::find($phoneId);
+        $this->assertEquals(1, $author->phone()->count());
+        $this->assertEquals($author->id, $phone->author_id);
+        $this->assertEquals('0404040404', $author->phone->number);
+
+        // New session
+        $sessionKey = uniqid('session_key', true);
+
+        // Deferred remove
+        $author->phone()->remove($phone, $sessionKey);
+        $this->assertEquals(1, $author->phone()->count());
+        $this->assertEquals(0, $author->phone()->withDeferred($sessionKey)->count());
+        $this->assertEquals($author->id, $phone->author_id);
+        $this->assertEquals('0404040404', $author->phone->number);
+
+        // Commit deferred
+        $author->save(null, $sessionKey);
+        $phone = Phone::find($phoneId);
+        $this->assertEquals(0, $author->phone()->count());
+        $this->assertNull($phone->author_id);
+        $this->assertNull($author->phone);
+    }
+}
\ No newline at end of file