diff --git a/Command/Tool/CalendarCommand.php b/Command/Tool/CalendarCommand.php
index 6a6a9f7..ad674ad 100644
--- a/Command/Tool/CalendarCommand.php
+++ b/Command/Tool/CalendarCommand.php
@@ -76,10 +76,11 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                         }
                         $time = sprintf('%02s:%02s', $parts[1], $parts[0]);
 
-                        $duplicates = array_filter($data, function ($row) use ($day, $time, $cron): bool {
-                            return $row[4]->getNextRunDate()->format('c') === $cron->getNextRunDate()->format('c');
-                            // return ($row[1] === $day && $row[3] === $time) || ($row[1] === '*' && $row[3] === $time) || ($day === '*' && $row[3] === $time);
-                        });
+                        $duplicates = array_filter(
+                            $data,
+                            fn (array $row): bool => $row[4]->getNextRunDate()->format('c') === $cron->getNextRunDate()->format('c')
+                            // fn (array $row): bool => ($row[1] === $day && $row[3] === $time) || ($row[1] === '*' && $row[3] === $time) || ($day === '*' && $row[3] === $time)
+                        );
                         $warning = count($duplicates) > 0 ? '⚠ Duplicate' : null;
 
                         $data[] = [
@@ -95,17 +96,18 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                 }
             }
 
-            $nextRun = array_map(function ($row) {
-                return $row[4]->getNextRunDate()->format('c');
-            }, $data);
+            $nextRun = array_map(
+                fn (array $row): string => $row[4]->getNextRunDate()->format('c'),
+                $data
+            );
             array_multisort(
                 $nextRun,
                 SORT_ASC,
                 $data
             );
 
-            $display = array_map(function ($row) {
-                return [
+            $display = array_map(
+                fn (array $row): array => [
                     $row[0],
                     $row[1],
                     $row[2],
@@ -113,8 +115,9 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                     $row[4]->getExpression(),
                     $row[4]->getNextRunDate()->format('d M Y H:i'),
                     $row[5],
-                ];
-            }, $data);
+                ],
+                $data
+            );
 
             $table = new Table($output);
             $table->setHeaders(['City', 'Day of week', 'Day of month', 'Time', 'Cron', 'Next run', '']);
diff --git a/Model/Details/Details.php b/Model/Details/Details.php
index 93edc57..005ce5f 100644
--- a/Model/Details/Details.php
+++ b/Model/Details/Details.php
@@ -11,7 +11,7 @@ class Details
     public ?array $labels;
     /** @var null|array<string,LanguageValue> */
     public ?array $descriptions;
-    /** @var array<string,string> */
+    /** @var array<string,object> */
     public ?array $nicknames;
     public ?int $birth;
     public ?int $death;
diff --git a/Model/GeoJSON/Feature.php b/Model/GeoJSON/Feature.php
index 69070af..9f904bb 100644
--- a/Model/GeoJSON/Feature.php
+++ b/Model/GeoJSON/Feature.php
@@ -12,7 +12,7 @@ class Feature implements JsonSerializable
     public Properties $properties;
     public ?Geometry $geometry;
 
-    public function jsonSerialize()
+    public function jsonSerialize(): array
     {
         return [
             'type' => $this->type,
diff --git a/Model/GeoJSON/FeatureCollection.php b/Model/GeoJSON/FeatureCollection.php
index 0b91d7b..d49277e 100644
--- a/Model/GeoJSON/FeatureCollection.php
+++ b/Model/GeoJSON/FeatureCollection.php
@@ -10,7 +10,7 @@ class FeatureCollection implements JsonSerializable
   /** @var Feature[] $features */
     public array $features = [];
 
-    public function jsonSerialize()
+    public function jsonSerialize(): array
     {
         return [
         'type' => $this->type,
diff --git a/Model/GeoJSON/Geometry/Geometry.php b/Model/GeoJSON/Geometry/Geometry.php
index b50708f..493b86f 100644
--- a/Model/GeoJSON/Geometry/Geometry.php
+++ b/Model/GeoJSON/Geometry/Geometry.php
@@ -19,7 +19,7 @@ public function __construct(array $coordinates)
         $this->coordinates = $coordinates;
     }
 
-    public function jsonSerialize()
+    public function jsonSerialize(): array
     {
         return [
             'type' => $this->type,
diff --git a/Model/GeoJSON/Properties.php b/Model/GeoJSON/Properties.php
index 3438015..a7c9a50 100644
--- a/Model/GeoJSON/Properties.php
+++ b/Model/GeoJSON/Properties.php
@@ -14,7 +14,7 @@ class Properties implements JsonSerializable
     /** @var null|Details|Details[] */
     public $details;
 
-    public function jsonSerialize()
+    public function jsonSerialize(): array
     {
         return [
         'name' => $this->name,
diff --git a/Wikidata/Wikidata.php b/Wikidata/Wikidata.php
index 32b70f0..6afbae6 100644
--- a/Wikidata/Wikidata.php
+++ b/Wikidata/Wikidata.php
@@ -93,7 +93,7 @@ public static function extractSitelinks($entity, array $languages): array
      * @param Entity $entity
      * @param string[] $languages
      *
-     * @return null|array<string,string>
+     * @return null|array<string,object>
      */
     public static function extractNicknames($entity, array $languages): ?array
     {
@@ -102,10 +102,12 @@ public static function extractNicknames($entity, array $languages): ?array
         $claims = $entity->claims->P1449 ?? [];
 
         foreach ($claims as $value) {
-            $language = $value->mainsnak->datavalue->value->language; // @phpstan-ignore-line
+            /** @var \stdClass */
+            $mainValue = $value->mainsnak->datavalue->value; // @phpstan-ignore-line
+            $language = $mainValue->language;
 
             if (in_array($language, $languages, true)) {
-                $nicknames[$language] = $value->mainsnak->datavalue->value; // @phpstan-ignore-line
+                $nicknames[$language] = $mainValue;
             }
         }