diff --git a/.phpstan.neon b/.phpstan.neon
index bf82db6d..828d8506 100644
--- a/.phpstan.neon
+++ b/.phpstan.neon
@@ -4,10 +4,5 @@ includes:
 
 parameters:
 	ignoreErrors:
-		# not convenient to mark every place with unnecessary check
-		- '#Cannot access property \$\w+ on Nextras\\Orm\\Entity\\Reflection\\PropertyRelationshipMetadata\|null\.#'
 		# https://github.com/phpstan/phpstan/issues/587
 		- '#Constructor of class Nextras\\Orm\\Bridges\\NetteDI\\DIRepositoryFinder has an unused parameter \$modelClass\.#'
-		# we need a local mute
-		- '#Cannot call method \w+\(\) on Nextras\\Dbal\\Result\\Result\|null\.#'
-		- '#Cannot call method \w+\(\) on Nextras\\Dbal\\Result\\Row\|null\.#'
diff --git a/.travis.yml b/.travis.yml
index a08cce23..1c6af50b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -33,7 +33,7 @@ before_script:
 
     # Install Nette Tester
     - phpenv config-rm xdebug.ini || true
-    - if [ "$dependencies" = "lowest" ]; then composer update --prefer-lowest --no-interaction; fi
+    - if [ "$dependencies" = "lowest" ]; then composer update --prefer-lowest --prefer-stable --no-interaction; fi
     - if [ "$dependencies" = "highest" ]; then composer update --no-interaction; fi
 
 script:
diff --git a/composer.json b/composer.json
index 8f7079cd..f16fcffb 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
 		"nette/caching": "~2.5 || ~3.0@rc",
 		"nette/utils": "~2.5 || ~3.0@rc",
 		"nette/tokenizer": "~2.3 || ~3.0@rc",
-		"nextras/dbal": "~3.0"
+		"nextras/dbal": "~3.0 || ~3.1@dev"
 	},
 	"require-dev": {
 		"nette/bootstrap": "~2.4 || ~3.0@rc",
@@ -33,8 +33,8 @@
 		"nette/tester": "~2.1",
 		"marc-mabe/php-enum": "~3.0",
 		"mockery/mockery": "~1.2",
-		"phpstan/phpstan-shim": "0.10.7",
-		"phpstan/phpstan-nette": "0.10.1",
+		"phpstan/phpstan-shim": "0.11.1",
+		"phpstan/phpstan-nette": "0.11",
 		"tracy/tracy": "~2.3"
 	},
 	"autoload": {
diff --git a/src/Entity/AbstractEntity.php b/src/Entity/AbstractEntity.php
index bac09692..d7f35df3 100644
--- a/src/Entity/AbstractEntity.php
+++ b/src/Entity/AbstractEntity.php
@@ -255,8 +255,11 @@ public function onLoad(array $data)
 	}
 
 
-	public function onRefresh(array $data, bool $isPartial = false)
+	public function onRefresh(?array $data, bool $isPartial = false)
 	{
+		if ($data === null) {
+			throw new InvalidStateException('Refetching data failed. Entity is not present in storage anymore.');
+		}
 		if ($isPartial) {
 			foreach ($data as $name => $value) {
 				$this->data[$name] = $value;
@@ -448,7 +451,7 @@ private function &internalGetValue(PropertyMetadata $metadata, string $name)
 		} else {
 			$value = $this->data[$name];
 		}
-		if (!isset($value) && !$metadata->isNullable) {
+		if ($value === null && !$metadata->isNullable) {
 			$class = get_class($this);
 			throw new InvalidStateException("Property {$class}::\${$name} is not set.");
 		}
diff --git a/src/Entity/IEntity.php b/src/Entity/IEntity.php
index 04507503..8ef98d52 100644
--- a/src/Entity/IEntity.php
+++ b/src/Entity/IEntity.php
@@ -125,7 +125,7 @@ public function onLoad(array $data);
 
 
 	/** @internal */
-	public function onRefresh(array $data, bool $isPartial = false);
+	public function onRefresh(?array $data, bool $isPartial = false);
 
 
 	/** @internal */
diff --git a/src/Mapper/Dbal/DbalMapper.php b/src/Mapper/Dbal/DbalMapper.php
index ef585696..ae9f9247 100644
--- a/src/Mapper/Dbal/DbalMapper.php
+++ b/src/Mapper/Dbal/DbalMapper.php
@@ -319,8 +319,12 @@ protected function processPostgreAutoupdate(IEntity $entity, array $args)
 		$args[] = 'RETURNING %ex';
 		$args[] = $this->getAutoupdateReselectExpression();
 		$row = $this->connection->queryArgs($args)->fetch();
-		$data = $this->getStorageReflection()->convertStorageToEntity($row->toArray());
-		$entity->onRefresh($data, true);
+		if ($row === null) {
+			$entity->onRefresh(null, true);
+		} else {
+			$data = $this->getStorageReflection()->convertStorageToEntity($row->toArray());
+			$entity->onRefresh($data, true);
+		}
 	}
 
 
@@ -342,8 +346,12 @@ protected function processMySQLAutoupdate(IEntity $entity, array $args)
 			$this->getTableName(),
 			$primary
 		)->fetch();
-		$data = $this->getStorageReflection()->convertStorageToEntity($row->toArray());
-		$entity->onRefresh($data, true);
+		if ($row === null) {
+			$entity->onRefresh(null, true);
+		} else {
+			$data = $this->getStorageReflection()->convertStorageToEntity($row->toArray());
+			$entity->onRefresh($data, true);
+		}
 	}
 
 
diff --git a/src/Mapper/Dbal/RelationshipMapperManyHasMany.php b/src/Mapper/Dbal/RelationshipMapperManyHasMany.php
index 391143bb..8285c641 100644
--- a/src/Mapper/Dbal/RelationshipMapperManyHasMany.php
+++ b/src/Mapper/Dbal/RelationshipMapperManyHasMany.php
@@ -265,6 +265,7 @@ public function remove(IEntity $parent, array $remove)
 
 	protected function buildList(IEntity $parent, array $entries): array
 	{
+		assert($this->metadata->relationship !== null);
 		if (!$this->metadata->relationship->isMain) {
 			throw new LogicException('ManyHasMany relationship has to be persisted in the primary mapper.');
 		}
diff --git a/src/Mapper/Dbal/RelationshipMapperOneHasMany.php b/src/Mapper/Dbal/RelationshipMapperOneHasMany.php
index f0a152da..714b88b7 100644
--- a/src/Mapper/Dbal/RelationshipMapperOneHasMany.php
+++ b/src/Mapper/Dbal/RelationshipMapperOneHasMany.php
@@ -16,6 +16,7 @@
 use Nextras\Orm\Entity\IEntity;
 use Nextras\Orm\Entity\IEntityHasPreloadContainer;
 use Nextras\Orm\Entity\Reflection\PropertyMetadata;
+use Nextras\Orm\Entity\Reflection\PropertyRelationshipMetadata;
 use Nextras\Orm\Mapper\IRelationshipMapper;
 
 
@@ -27,6 +28,9 @@ class RelationshipMapperOneHasMany implements IRelationshipMapper
 	/** @var PropertyMetadata */
 	protected $metadata;
 
+	/** @var PropertyRelationshipMetadata */
+	protected $metadataRelationship;
+
 	/** @var DbalMapper */
 	protected $targetMapper;
 
@@ -47,6 +51,7 @@ public function __construct(IConnection $connection, DbalMapper $targetMapper, P
 		$this->connection = $connection;
 		$this->targetMapper = $targetMapper;
 		$this->metadata = $metadata;
+		$this->metadataRelationship = $metadata->relationship;
 		$this->joinStorageKey = $targetMapper->getStorageReflection()->convertEntityToStorageKey($metadata->relationship->property);
 	}
 
@@ -103,7 +108,7 @@ protected function fetchByOnePassStrategy(QueryBuilder $builder, array $values):
 		$result = $this->connection->queryArgs($builder->getQuerySql(), $builder->getQueryParameters());
 		$entities = [];
 
-		$property = $this->metadata->relationship->property;
+		$property = $this->metadataRelationship->property;
 		assert($property !== null);
 
 		while (($data = $result->fetch())) {
@@ -122,7 +127,7 @@ protected function fetchByTwoPassStrategy(QueryBuilder $builder, array $values):
 		$builder = clone $builder;
 		$targetPrimaryKey = array_map(function ($key) {
 			return $this->targetMapper->getStorageReflection()->convertEntityToStorageKey($key);
-		}, $this->metadata->relationship->entityMetadata->getPrimaryKey());
+		}, $this->metadataRelationship->entityMetadata->getPrimaryKey());
 		$isComposite = count($targetPrimaryKey) !== 1;
 
 		foreach (array_unique(array_merge($targetPrimaryKey, [$this->joinStorageKey])) as $key) {
@@ -172,7 +177,7 @@ protected function fetchByTwoPassStrategy(QueryBuilder $builder, array $values):
 		foreach ($map as $joiningStorageKey => $primaryValues) {
 			foreach ($primaryValues as $primaryValue) {
 				$entity = $entitiesResult[$primaryValue];
-				$entities[$entity->getRawValue($this->metadata->relationship->property)][] = $entity;
+				$entities[$entity->getRawValue($this->metadataRelationship->property)][] = $entity;
 			}
 		}
 
diff --git a/src/Mapper/Dbal/StorageReflection/StorageReflection.php b/src/Mapper/Dbal/StorageReflection/StorageReflection.php
index 9c003e9e..9199f0f6 100644
--- a/src/Mapper/Dbal/StorageReflection/StorageReflection.php
+++ b/src/Mapper/Dbal/StorageReflection/StorageReflection.php
@@ -229,6 +229,7 @@ public function addModifier(string $storageKey, string $saveModifier): StorageRe
 
 	protected function findManyHasManyPrimaryColumns($joinTable, $sourceTable, $targetTable): array
 	{
+		$sourceId = $targetId = null;
 		$useFQN = strpos($sourceTable, '.') !== false;
 		$keys = $this->platform->getForeignKeys($joinTable);
 		foreach ($keys as $column => $meta) {
@@ -236,14 +237,14 @@ protected function findManyHasManyPrimaryColumns($joinTable, $sourceTable, $targ
 				? $meta['ref_table']
 				: preg_replace('#^(.*\.)?(.*)$#', '$2', $meta['ref_table']);
 
-			if ($table === $sourceTable && !isset($sourceId)) {
+			if ($table === $sourceTable && $sourceId === null) {
 				$sourceId = $column;
 			} elseif ($table === $targetTable) {
 				$targetId = $column;
 			}
 		}
 
-		if (!isset($sourceId, $targetId)) {
+		if ($sourceId === null || $targetId === null) {
 			throw new InvalidStateException("No primary keys detected for many has many '{$joinTable}' join table.");
 		}
 
diff --git a/src/Mapper/Memory/RelationshipMapperManyHasMany.php b/src/Mapper/Memory/RelationshipMapperManyHasMany.php
index b2397fb4..a221455a 100644
--- a/src/Mapper/Memory/RelationshipMapperManyHasMany.php
+++ b/src/Mapper/Memory/RelationshipMapperManyHasMany.php
@@ -27,7 +27,6 @@ class RelationshipMapperManyHasMany implements IRelationshipMapperManyHasMany
 
 	public function __construct(PropertyMetadata $metadata, ArrayMapper $mapper)
 	{
-		assert($metadata->relationship !== null);
 		$this->metadata = $metadata;
 		$this->mapper = $mapper;
 	}
@@ -43,6 +42,7 @@ public function clearCache()
 	 */
 	public function getIterator(IEntity $parent, ICollection $collection): Iterator
 	{
+		assert($this->metadata->relationship !== null);
 		if ($this->metadata->relationship->isMain) {
 			$relationshipData = $this->mapper->getRelationshipDataStorage($this->metadata->name);
 			$id = $parent->getValue('id');
diff --git a/src/Mapper/Memory/RelationshipMapperOneHasMany.php b/src/Mapper/Memory/RelationshipMapperOneHasMany.php
index 291a073a..1ef97529 100644
--- a/src/Mapper/Memory/RelationshipMapperOneHasMany.php
+++ b/src/Mapper/Memory/RelationshipMapperOneHasMany.php
@@ -13,6 +13,7 @@
 use Nextras\Orm\Collection\ICollection;
 use Nextras\Orm\Entity\IEntity;
 use Nextras\Orm\Entity\Reflection\PropertyMetadata;
+use Nextras\Orm\Entity\Reflection\PropertyRelationshipMetadata;
 use Nextras\Orm\Mapper\IRelationshipMapper;
 
 
@@ -39,11 +40,9 @@ public function clearCache()
 	}
 
 
-	/**
-	 * @return EntityIterator
-	 */
 	public function getIterator(IEntity $parent, ICollection $collection): Iterator
 	{
+		assert($this->metadata->relationship !== null);
 		$className = $this->metadata->relationship->entityMetadata->className;
 		$data = $collection->findBy(["$className->{$this->joinStorageKey}->id" => $parent->getValue('id')])->fetchAll();
 		return new EntityIterator($data);
@@ -52,6 +51,8 @@ public function getIterator(IEntity $parent, ICollection $collection): Iterator
 
 	public function getIteratorCount(IEntity $parent, ICollection $collection): int
 	{
-		return count($this->getIterator($parent, $collection));
+		$iterator = $this->getIterator($parent, $collection);
+		assert($iterator instanceof \Countable);
+		return count($iterator);
 	}
 }
diff --git a/src/Relationships/HasMany.php b/src/Relationships/HasMany.php
index 662bf0a1..bc7bb321 100644
--- a/src/Relationships/HasMany.php
+++ b/src/Relationships/HasMany.php
@@ -14,6 +14,7 @@
 use Nextras\Orm\Collection\ICollection;
 use Nextras\Orm\Entity\IEntity;
 use Nextras\Orm\Entity\Reflection\PropertyMetadata;
+use Nextras\Orm\Entity\Reflection\PropertyRelationshipMetadata;
 use Nextras\Orm\InvalidStateException;
 use Nextras\Orm\Mapper\IRelationshipMapper;
 use Nextras\Orm\Repository\IRepository;
@@ -30,6 +31,9 @@ abstract class HasMany implements IRelationshipCollection
 	/** @var PropertyMetadata */
 	protected $metadata;
 
+	/** @var PropertyRelationshipMetadata */
+	protected $metadataRelationship;
+
 	/** @var ICollection|null */
 	protected $collection;
 
@@ -62,6 +66,7 @@ public function __construct(PropertyMetadata $metadata)
 	{
 		assert($metadata->relationship !== null);
 		$this->metadata = $metadata;
+		$this->metadataRelationship = $metadata->relationship;
 	}
 
 
@@ -339,7 +344,7 @@ public function __clone()
 	protected function getTargetRepository(): IRepository
 	{
 		if (!$this->targetRepository) {
-			$this->targetRepository = $this->parent->getRepository()->getModel()->getRepository($this->metadata->relationship->repository);
+			$this->targetRepository = $this->parent->getRepository()->getModel()->getRepository($this->metadataRelationship->repository);
 		}
 
 		return $this->targetRepository;
@@ -360,8 +365,8 @@ protected function getRelationshipMapper()
 
 	protected function applyDefaultOrder(ICollection $collection)
 	{
-		if ($this->metadata->relationship->order !== null) {
-			return $collection->orderBy($this->metadata->relationship->order);
+		if ($this->metadataRelationship->order !== null) {
+			return $collection->orderBy($this->metadataRelationship->order);
 		} else {
 			return $collection;
 		}
diff --git a/src/Relationships/HasOne.php b/src/Relationships/HasOne.php
index dc6e59fc..ecee80c0 100644
--- a/src/Relationships/HasOne.php
+++ b/src/Relationships/HasOne.php
@@ -12,6 +12,7 @@
 use Nextras\Orm\Collection\ICollection;
 use Nextras\Orm\Entity\IEntity;
 use Nextras\Orm\Entity\Reflection\PropertyMetadata;
+use Nextras\Orm\Entity\Reflection\PropertyRelationshipMetadata;
 use Nextras\Orm\InvalidArgumentException;
 use Nextras\Orm\Mapper\IRelationshipMapper;
 use Nextras\Orm\NullValueException;
@@ -29,6 +30,9 @@ abstract class HasOne implements IRelationshipContainer
 	/** @var PropertyMetadata */
 	protected $metadata;
 
+	/** @var PropertyRelationshipMetadata */
+	protected $metadataRelationship;
+
 	/** @var ICollection */
 	protected $collection;
 
@@ -55,6 +59,7 @@ public function __construct(PropertyMetadata $metadata)
 	{
 		assert($metadata->relationship !== null);
 		$this->metadata = $metadata;
+		$this->metadataRelationship = $metadata->relationship;
 	}
 
 
@@ -195,7 +200,7 @@ protected function getPrimaryValue()
 	protected function getTargetRepository(): IRepository
 	{
 		if (!$this->targetRepository) {
-			$this->targetRepository = $this->parent->getRepository()->getModel()->getRepository($this->metadata->relationship->repository);
+			$this->targetRepository = $this->parent->getRepository()->getModel()->getRepository($this->metadataRelationship->repository);
 		}
 
 		return $this->targetRepository;
@@ -216,7 +221,7 @@ protected function createEntity($entity, bool $allowNull)
 	{
 		if ($entity instanceof IEntity) {
 			if ($this->parent->isAttached()) {
-				$repository = $this->parent->getRepository()->getModel()->getRepository($this->metadata->relationship->repository);
+				$repository = $this->parent->getRepository()->getModel()->getRepository($this->metadataRelationship->repository);
 				$repository->attach($entity);
 
 			} elseif ($entity->isAttached()) {
diff --git a/src/Relationships/ManyHasMany.php b/src/Relationships/ManyHasMany.php
index ae515a2b..c35eeecb 100644
--- a/src/Relationships/ManyHasMany.php
+++ b/src/Relationships/ManyHasMany.php
@@ -44,7 +44,7 @@ public function doPersist()
 		$this->isModified = false;
 		$this->collection = null;
 
-		if ($this->metadata->relationship->isMain) {
+		if ($this->metadataRelationship->isMain) {
 			$this->getRelationshipMapper()->clearCache();
 			$this->getRelationshipMapper()->remove($this->parent, $toRemove);
 			$this->getRelationshipMapper()->add($this->parent, $toAdd);
@@ -60,7 +60,7 @@ protected function modify(): void
 
 	protected function createCollection(): ICollection
 	{
-		if ($this->metadata->relationship->isMain) {
+		if ($this->metadataRelationship->isMain) {
 			$mapperOne = $this->parent->getRepository()->getMapper();
 			$mapperTwo = $this->getTargetRepository()->getMapper();
 		} else {
@@ -71,11 +71,11 @@ protected function createCollection(): ICollection
 		$collection = $mapperOne->createCollectionManyHasMany($mapperTwo, $this->metadata);
 		$collection = $collection->setRelationshipParent($this->parent);
 		$collection->subscribeOnEntityFetch(function (Traversable $entities) {
-			if (!$this->metadata->relationship->property) {
+			if (!$this->metadataRelationship->property) {
 				return;
 			}
 			foreach ($entities as $entity) {
-				$entity->getProperty($this->metadata->relationship->property)->trackEntity($this->parent);
+				$entity->getProperty($this->metadataRelationship->property)->trackEntity($this->parent);
 				$this->trackEntity($entity);
 			}
 		});
@@ -85,11 +85,11 @@ protected function createCollection(): ICollection
 
 	protected function updateRelationshipAdd(IEntity $entity): void
 	{
-		if (!$this->metadata->relationship->property) {
+		if (!$this->metadataRelationship->property) {
 			return;
 		}
 
-		$otherSide = $entity->getProperty($this->metadata->relationship->property);
+		$otherSide = $entity->getProperty($this->metadataRelationship->property);
 		assert($otherSide instanceof ManyHasMany);
 		$otherSide->collection = null;
 		$otherSide->toAdd[spl_object_hash($this->parent)] = $this->parent;
@@ -99,11 +99,11 @@ protected function updateRelationshipAdd(IEntity $entity): void
 
 	protected function updateRelationshipRemove(IEntity $entity): void
 	{
-		if (!$this->metadata->relationship->property) {
+		if (!$this->metadataRelationship->property) {
 			return;
 		}
 
-		$otherSide = $entity->getProperty($this->metadata->relationship->property);
+		$otherSide = $entity->getProperty($this->metadataRelationship->property);
 		assert($otherSide instanceof ManyHasMany);
 		$otherSide->collection = null;
 		$otherSide->toRemove[spl_object_hash($this->parent)] = $this->parent;
diff --git a/src/Relationships/ManyHasOne.php b/src/Relationships/ManyHasOne.php
index 6770fba4..f873732d 100644
--- a/src/Relationships/ManyHasOne.php
+++ b/src/Relationships/ManyHasOne.php
@@ -30,7 +30,7 @@ protected function modify(): void
 
 	protected function updateRelationship(?IEntity $oldEntity, ?IEntity $newEntity, bool $allowNull): void
 	{
-		$key = $this->metadata->relationship->property;
+		$key = $this->metadataRelationship->property;
 		if (!$key) {
 			return;
 		}
@@ -49,7 +49,7 @@ protected function updateRelationship(?IEntity $oldEntity, ?IEntity $newEntity,
 
 	protected function initReverseRelationship(?IEntity $entity)
 	{
-		$key = $this->metadata->relationship->property;
+		$key = $this->metadataRelationship->property;
 		if (!$key || !$entity) {
 			return;
 		}
diff --git a/src/Relationships/OneHasMany.php b/src/Relationships/OneHasMany.php
index b8d161cf..5cd4cd5d 100644
--- a/src/Relationships/OneHasMany.php
+++ b/src/Relationships/OneHasMany.php
@@ -66,24 +66,24 @@ protected function createCollection(): ICollection
 
 	protected function updateRelationshipAdd(IEntity $entity): void
 	{
-		if (!$this->metadata->relationship->property) {
+		if (!$this->metadataRelationship->property) {
 			return;
 		}
 
 		$this->updatingReverseRelationship = true;
-		$entity->getProperty($this->metadata->relationship->property)->setInjectedValue($entity, $this->parent);
+		$entity->getProperty($this->metadataRelationship->property)->setInjectedValue($entity, $this->parent);
 		$this->updatingReverseRelationship = false;
 	}
 
 
 	protected function updateRelationshipRemove(IEntity $entity): void
 	{
-		if (!$this->metadata->relationship->property) {
+		if (!$this->metadataRelationship->property) {
 			return;
 		}
 
 		$this->updatingReverseRelationship = true;
-		$entity->getProperty($this->metadata->relationship->property)->setInjectedValue($entity, null);
+		$entity->getProperty($this->metadataRelationship->property)->setInjectedValue($entity, null);
 		$this->updatingReverseRelationship = false;
 	}
 }
diff --git a/src/Relationships/OneHasOne.php b/src/Relationships/OneHasOne.php
index 25a3985f..5c20dfd3 100644
--- a/src/Relationships/OneHasOne.php
+++ b/src/Relationships/OneHasOne.php
@@ -23,7 +23,7 @@ protected function createCollection(): ICollection
 
 	public function getRawValue()
 	{
-		if ($this->primaryValue === null && $this->value === false && !$this->metadata->relationship->isMain) {
+		if ($this->primaryValue === null && $this->value === false && !$this->metadataRelationship->isMain) {
 			$this->getEntity(); // init the value
 		}
 		return parent::getRawValue();
@@ -33,7 +33,7 @@ public function getRawValue()
 	protected function modify(): void
 	{
 		$this->isModified = true;
-		if ($this->metadata->relationship->isMain) {
+		if ($this->metadataRelationship->isMain) {
 			$this->parent->setAsModified($this->metadata->name);
 		}
 	}
@@ -41,7 +41,7 @@ protected function modify(): void
 
 	protected function updateRelationship(?IEntity $oldEntity, ?IEntity $newEntity, bool $allowNull): void
 	{
-		$key = $this->metadata->relationship->property;
+		$key = $this->metadataRelationship->property;
 		if (!$key) {
 			return;
 		}
@@ -59,7 +59,7 @@ protected function updateRelationship(?IEntity $oldEntity, ?IEntity $newEntity,
 
 	protected function initReverseRelationship(?IEntity $entity)
 	{
-		$key = $this->metadata->relationship->property;
+		$key = $this->metadataRelationship->property;
 		if (!$key || !$entity) {
 			return;
 		}
diff --git a/src/Repository/IdentityMap.php b/src/Repository/IdentityMap.php
index cc015e98..391b2b8f 100644
--- a/src/Repository/IdentityMap.php
+++ b/src/Repository/IdentityMap.php
@@ -20,7 +20,7 @@ class IdentityMap
 	/** @var IRepository */
 	private $repository;
 
-	/** @var array of IEntity|bool */
+	/** @var array<IEntity|false> */
 	private $entities = [];
 
 	/** @var array */
diff --git a/src/TestHelper/EntityCreator.php b/src/TestHelper/EntityCreator.php
index ee9319b9..43ff8624 100644
--- a/src/TestHelper/EntityCreator.php
+++ b/src/TestHelper/EntityCreator.php
@@ -98,7 +98,7 @@ protected function random(PropertyMetadata $property)
 			}
 		}
 
-		if (!$possibilities) {
+		if (count($possibilities) === 0) {
 			return null;
 		}
 
diff --git a/tests/cases/integration/Mapper/DbalPersistAutoupdateMapperTest.phpt b/tests/cases/integration/Mapper/DbalPersistAutoupdateMapperTest.phpt
index c8cf5f86..9a15ac4c 100644
--- a/tests/cases/integration/Mapper/DbalPersistAutoupdateMapperTest.phpt
+++ b/tests/cases/integration/Mapper/DbalPersistAutoupdateMapperTest.phpt
@@ -9,6 +9,9 @@ namespace NextrasTests\Orm\Integration\Mapper;
 
 use DateTime;
 use DateTimeImmutable;
+use Nextras\Dbal\Connection;
+use Nextras\Dbal\IConnection;
+use Nextras\Orm\InvalidStateException;
 use NextrasTests\Orm\BookCollection;
 use NextrasTests\Orm\DataTestCase;
 use NextrasTests\Orm\Helper;
@@ -48,6 +51,15 @@ class DbalPersistAutoupdateMapperTest extends DataTestCase
 		Assert::type(DateTimeImmutable::class, $bookCollection->updatedAt);
 		$new = $bookCollection->updatedAt;
 		Assert::notEqual($old->format(DateTime::ISO8601), $new->format(DateTime::ISO8601));
+
+		/** @var IConnection $connection */
+		$connection = $this->container->getByType(Connection::class);
+		$connection->query('DELETE FROM book_collections WHERE id = %i', $bookCollection->id);
+
+		$bookCollection->name .= '2';
+		Assert::exception(function () use ($bookCollection) {
+			$this->orm->bookColletions->persistAndFlush($bookCollection);
+		}, InvalidStateException::class, 'Refetching data failed. Entity is not present in storage anymore.');
 	}
 }