diff --git a/lib/Model.php b/lib/Model.php
index 4c597f1b..d2cc0804 100644
--- a/lib/Model.php
+++ b/lib/Model.php
@@ -224,6 +224,11 @@ class Model
      */
     public static array $has_many;
 
+    /**
+     * @var array<string,HasManyOptions>
+     */
+    public static array $has_one;
+
     /**
      * @var array<string,BelongsToOptions>
      */
diff --git a/lib/Relationship/HasOne.php b/lib/Relationship/HasOne.php
index 9f9cdbd2..3dfccaa3 100644
--- a/lib/Relationship/HasOne.php
+++ b/lib/Relationship/HasOne.php
@@ -2,6 +2,8 @@
 
 namespace ActiveRecord\Relationship;
 
+use ActiveRecord\Types;
+
 /**
  * One-to-one relationship.
  *
@@ -13,16 +15,26 @@
  * # Table name: people
  * # Foreign key: state_id
  * class Person extends ActiveRecord\Model {
- *   static $has_one = array(array('state'));
+ *   static array $has_one = [
+ *    'state' => true
+ *   ];
  * }
  * ```
  *
- * @package ActiveRecord
+ * @phpstan-import-type HasManyOptions from Types
  *
  * @see http://www.phpactiverecord.org/guides/associations
  */
 class HasOne extends HasMany
 {
+    /**
+     * @param HasManyOptions $options
+     */
+    public function __construct(string $attribute, array $options = [])
+    {
+        parent::__construct($attribute, $options);
+    }
+
     public function is_poly(): bool
     {
         return false;
diff --git a/lib/Table.php b/lib/Table.php
index 08ffeff9..583f14b5 100644
--- a/lib/Table.php
+++ b/lib/Table.php
@@ -594,7 +594,7 @@ private function set_associations(): void
                         break;
 
                     case 'has_one':
-                        $relationship = new HasOne($definition[0], $definition);
+                        $relationship = new HasOne($attribute, $definition);
                         break;
 
                     case 'belongs_to':
diff --git a/test/RelationshipTest.php b/test/RelationshipTest.php
index de2f8a11..0bc53466 100644
--- a/test/RelationshipTest.php
+++ b/test/RelationshipTest.php
@@ -55,7 +55,9 @@ public function setUp($connection_name=null): void
             ]
         ];
         Venue::$has_one = [];
-        Employee::$has_one = [['position']];
+        Employee::$has_one = [
+            'position' => []
+        ];
         Host::$has_many = [
             'events' => [
                 'order' => 'id asc'
@@ -516,7 +518,9 @@ public function testHasManyThroughWithInvalidClassName()
         Event::$belongs_to = [
             'host' => true
         ];
-        Venue::$has_one = [['invalid_assoc']];
+        Venue::$has_one = [
+            'invalid_assoc' => true
+        ];
         Venue::$has_many = [
             'hosts' => [
                 'through' => 'invalid_assoc'
@@ -557,13 +561,18 @@ public function testHasOneBasic()
 
     public function testHasOneWithExplicitClassName()
     {
-        Employee::$has_one = [['explicit_class_name', 'class_name' => 'Position']];
+        Employee::$has_one = [
+            'explicit_class_name' => [
+                'class_name' => 'Position'
+            ]
+        ];
         $this->assert_default_has_one($this->get_relationship(), 'explicit_class_name');
     }
 
     public function testHasOneWithSelect()
     {
-        Employee::$has_one[0]['select'] = 'title';
+        $ho = Employee::$has_one;
+        Employee::$has_one['position']['select'] = 'title';
         $employee = $this->get_relationship();
         $this->assert_default_has_one($employee);
 
@@ -577,7 +586,7 @@ public function testHasOneWithSelect()
 
     public function testHasOneWithOrder()
     {
-        Employee::$has_one[0]['order'] = 'title';
+        Employee::$has_one['position']['order'] = 'title';
         $employee = $this->get_relationship();
         $this->assert_default_has_one($employee);
         $this->assert_sql_has('ORDER BY title', Position::table()->last_sql);
@@ -585,7 +594,7 @@ public function testHasOneWithOrder()
 
     public function testHasOneWithConditionsAndNonQualifyingRecord()
     {
-        Employee::$has_one[0]['conditions'] = "title = 'programmer'";
+        Employee::$has_one['position']['conditions'] = "title = 'programmer'";
         $employee = $this->get_relationship();
         $this->assertEquals(1, $employee->id);
         $this->assertNull($employee->position);
@@ -593,13 +602,13 @@ public function testHasOneWithConditionsAndNonQualifyingRecord()
 
     public function testHasOneWithConditionsAndQualifyingRecord()
     {
-        Employee::$has_one[0]['conditions'] = "title = 'physicist'";
+        Employee::$has_one['position']['conditions'] = "title = 'physicist'";
         $this->assert_default_has_one($this->get_relationship());
     }
 
     public function testHasOneWithReadonly()
     {
-        Employee::$has_one[0]['readonly'] = true;
+        Employee::$has_one['position']['readonly'] = true;
         $employee = $this->get_relationship();
         $this->assert_default_has_one($employee);
 
@@ -629,7 +638,13 @@ public function testHasOneWithJoins()
 
     public function testHasOneWithExplicitKeys()
     {
-        Book::$has_one = [['explicit_author', 'class_name' => 'Author', 'foreign_key' => 'parent_author_id', 'primary_key' => 'secondary_author_id']];
+        Book::$has_one = [
+            'explicit_author' => [
+                'class_name' => 'Author',
+                'foreign_key' => 'parent_author_id',
+                'primary_key' => 'secondary_author_id'
+            ]
+        ];
 
         $book = Book::find(1);
         $this->assertEquals($book->secondary_author_id, $book->explicit_author->parent_author_id);
diff --git a/test/models/Author.php b/test/models/Author.php
index 6a4757ad..8d1702db 100644
--- a/test/models/Author.php
+++ b/test/models/Author.php
@@ -7,14 +7,19 @@
 class Author extends Model
 {
     public static $pk = 'author_id';
-    //	static $has_one = array(array('awesome_person', 'foreign_key' => 'author_id', 'primary_key' => 'author_id'),
-    //	array('parent_author', 'class_name' => 'Author', 'foreign_key' => 'parent_author_id'));
     public static array $has_many = [
         'books' => true
     ];
-    public static $has_one = [
-        ['awesome_person', 'foreign_key' => 'author_id', 'primary_key' => 'author_id'],
-        ['parent_author', 'class_name' => 'Author', 'foreign_key' => 'parent_author_id']];
+    public static array $has_one = [
+        'awesome_person' => [
+            'foreign_key' => 'author_id',
+            'primary_key' => 'author_id'
+        ],
+        'parent_author' => [
+            'class_name' => 'Author',
+            'foreign_key' => 'parent_author_id'
+        ]
+    ];
     public static array $belongs_to = [];
 
     public function set_password($plaintext)
diff --git a/test/models/AuthorAttrAccessible.php b/test/models/AuthorAttrAccessible.php
index a1430f0e..93d5c83b 100644
--- a/test/models/AuthorAttrAccessible.php
+++ b/test/models/AuthorAttrAccessible.php
@@ -15,8 +15,12 @@ class AuthorAttrAccessible extends Model
             'primary_key' => 'book_id'
         ]
     ];
-    public static $has_one = [
-        ['parent_author', 'class_name' => 'AuthorAttrAccessible', 'foreign_key' => 'parent_author_id', 'primary_key' => 'author_id']
+    public static array $has_one = [
+        'parent_author' => [
+            'class_name' => 'AuthorAttrAccessible',
+            'foreign_key' => 'parent_author_id',
+            'primary_key' => 'author_id'
+        ]
     ];
     public static array $belongs_to = [];
 
diff --git a/test/models/Book.php b/test/models/Book.php
index c55ac0c4..5f89ed0f 100644
--- a/test/models/Book.php
+++ b/test/models/Book.php
@@ -9,7 +9,7 @@ class Book extends Model
     public static array $belongs_to = [
         'author' => true
     ];
-    public static $has_one = [];
+    public static array $has_one = [];
 
     public function upper_name()
     {
diff --git a/test/models/Employee.php b/test/models/Employee.php
index 90269a64..619f7502 100644
--- a/test/models/Employee.php
+++ b/test/models/Employee.php
@@ -6,5 +6,5 @@
 
 class Employee extends Model
 {
-    public static $has_one;
+    public static array $has_one;
 }