diff --git a/src/Schematic/Entry.php b/src/Schematic/Entry.php
index 33106f7..3de1707 100644
--- a/src/Schematic/Entry.php
+++ b/src/Schematic/Entry.php
@@ -11,6 +11,7 @@ class Entry
 	const INDEX_ENTRYCLASS = 0;
 	const INDEX_MULTIPLICITY = 1;
 	const INDEX_EMBEDDING = 2;
+	const INDEX_NULLABLE = 3;
 
 	/**
 	 * @var array
@@ -64,18 +65,19 @@ private static function parseAssociations($class)
 
 		foreach (static::$associations as $association => $entryClass) {
 			$matches = [];
-			$result = preg_match('#^([^.[\]]+)(\.[^.[\]]*)?(\[\])?$#', $association, $matches);
+			$result = preg_match('#^(\?)?([^.[\]]+)(\.[^.[\]]*)?(\[\])?$#', $association, $matches);
 
-			if ($result === 0 || (!empty($matches[2]) && !empty($matches[3]))) {
+			if ($result === 0 || (!empty($matches[3]) && !empty($matches[4]))) {
 				throw new InvalidArgumentException('Invalid association definition given: ' . $association);
 			}
 
-			self::$parsedAssociations[$class][$matches[1]] = [
+			self::$parsedAssociations[$class][$matches[2]] = [
 				self::INDEX_ENTRYCLASS => $entryClass,
-				self::INDEX_MULTIPLICITY => !empty($matches[3]),
-				self::INDEX_EMBEDDING => !empty($matches[2]) ?
-					($matches[2] === '.' ? $matches[1] . '_' : substr($matches[2], 1)) :
+				self::INDEX_MULTIPLICITY => !empty($matches[4]),
+				self::INDEX_EMBEDDING => !empty($matches[3]) ?
+					($matches[3] === '.' ? $matches[2] . '_' : substr($matches[3], 1)) :
 					FALSE,
+				self::INDEX_NULLABLE => !empty($matches[1]),
 			];
 		}
 	}
@@ -101,7 +103,7 @@ public function __get($name)
 			$this->readEmbeddedEntry($association[self::INDEX_EMBEDDING]) :
 			$this->readData($name);
 
-		if ($data === NULL) {
+		if ($data === NULL || ($association[self::INDEX_NULLABLE] && empty($data))) {
 			return $this->data[$name] = NULL;
 		}
 
diff --git a/tests/SchematicTests/EntryTest.phpt b/tests/SchematicTests/EntryTest.phpt
index ba7ad8a..12f69d4 100644
--- a/tests/SchematicTests/EntryTest.phpt
+++ b/tests/SchematicTests/EntryTest.phpt
@@ -56,6 +56,16 @@ class EntryTest extends TestCase
 	}
 
 
+	public function testEntriesAccessToNullableParameter()
+	{
+		$order = new Order([
+			'customer' => [],
+			'orderItems' => [],
+		]);
+		Assert::null($order->customer);
+	}
+
+
 	public function testEntriesClass()
 	{
 		$order = new Order([
diff --git a/tests/SchematicTests/entries.php b/tests/SchematicTests/entries.php
index 67f0936..ec0082d 100644
--- a/tests/SchematicTests/entries.php
+++ b/tests/SchematicTests/entries.php
@@ -26,7 +26,7 @@ class Order extends Identified
 {
 
 	protected static $associations = [
-		'customer' => Customer::class,
+		'?customer' => Customer::class,
 		'orderItems[]' => OrderItem::class,
 	];