diff --git a/.phan/config.php b/.phan/config.php
index 05b92c0bdc..c421f1e623 100644
--- a/.phan/config.php
+++ b/.phan/config.php
@@ -65,7 +65,6 @@
 $cfg['exclude_analysis_directory_list'] = array_merge(
 	$cfg['exclude_analysis_directory_list'],
 	[
-		'lib/packages/wikibase/data-model-serialization/src/',
 		'lib/packages/wikibase/data-model-services/src/',
 		'lib/packages/wikibase/internal-serialization/src/',
 		'../../extensions/Babel/',
diff --git a/lib/packages/wikibase/data-model-serialization/src/Deserializers/SnakDeserializer.php b/lib/packages/wikibase/data-model-serialization/src/Deserializers/SnakDeserializer.php
index 73a6a0d29e..c82f247c4b 100644
--- a/lib/packages/wikibase/data-model-serialization/src/Deserializers/SnakDeserializer.php
+++ b/lib/packages/wikibase/data-model-serialization/src/Deserializers/SnakDeserializer.php
@@ -159,7 +159,7 @@ private function needsDataTypeLookup( string $valueType ): bool {
 			array_keys( $this->dataTypeToValueTypeMap, $valueType, true )
 		);
 
-		return !empty( array_intersect( $possibleDataTypeKeys, array_keys( $this->deserializerBuilders ) ) );
+		return array_intersect( $possibleDataTypeKeys, array_keys( $this->deserializerBuilders ) ) !== [];
 	}
 
 	/**
diff --git a/lib/packages/wikibase/data-model-serialization/src/Serializers/AliasGroupListSerializer.php b/lib/packages/wikibase/data-model-serialization/src/Serializers/AliasGroupListSerializer.php
index 29153961e1..3d4455db73 100644
--- a/lib/packages/wikibase/data-model-serialization/src/Serializers/AliasGroupListSerializer.php
+++ b/lib/packages/wikibase/data-model-serialization/src/Serializers/AliasGroupListSerializer.php
@@ -26,7 +26,7 @@ public function __construct( AliasGroupSerializer $aliasGroupSerializer, bool $u
 
 	/**
 	 * @param AliasGroupList $object
-	 * @return array|::stdClass
+	 * @return array|\stdClass
 	 */
 	public function serialize( $object ) {
 		$this->assertIsSerializerFor( $object );
diff --git a/lib/packages/wikibase/data-model-serialization/src/Serializers/MapSerializer.php b/lib/packages/wikibase/data-model-serialization/src/Serializers/MapSerializer.php
index 98d6dcf48c..58e5f88101 100644
--- a/lib/packages/wikibase/data-model-serialization/src/Serializers/MapSerializer.php
+++ b/lib/packages/wikibase/data-model-serialization/src/Serializers/MapSerializer.php
@@ -31,7 +31,7 @@ public function __construct( bool $useObjectsForEmptyMaps ) {
 	 * @return array|\stdClass
 	 */
 	protected function serializeMap( array $serialization ) {
-		if ( $this->useObjectsForEmptyMaps && empty( $serialization ) ) {
+		if ( $this->useObjectsForEmptyMaps && $serialization === [] ) {
 			$serialization = (object)$serialization;
 		}