diff --git a/rector.php b/rector.php
index dac564c2..99a3024c 100644
--- a/rector.php
+++ b/rector.php
@@ -17,7 +17,7 @@
 return RectorConfig::configure()
     ->withPaths(['src'])
     ->withPhpSets(php81: true)
-    //->withPreparedSets(deadCode: true, codingStyle: true, typeDeclarations: true)
+    ->withPreparedSets(deadCode: true, typeDeclarations: true)
     ->withSkip([
         NullToStrictStringFuncCallArgRector::class,
         ClosureToArrowFunctionRector::class,
diff --git a/src/Countries/Benin.php b/src/Countries/Benin.php
index 7e797920..b6a5b9a5 100644
--- a/src/Countries/Benin.php
+++ b/src/Countries/Benin.php
@@ -354,6 +354,6 @@ protected function prepareHolidays(
             $holidays[$prefix.$label.' - Jour '.$range] = $holiday->addDays($range - 1);
         }
 
-        return array_filter($holidays, fn ($holiday) => $holiday->year == $filterYear);
+        return array_filter($holidays, fn ($holiday): bool => $holiday->year == $filterYear);
     }
 }
diff --git a/src/Countries/Country.php b/src/Countries/Country.php
index 4fbf79b7..c2a5b627 100644
--- a/src/Countries/Country.php
+++ b/src/Countries/Country.php
@@ -46,7 +46,7 @@ public function get(int $year, ?string $locale = null): array
         }
 
         uasort($translatedHolidays,
-            fn (CarbonImmutable $a, CarbonImmutable $b) => $a->timestamp <=> $b->timestamp
+            fn (CarbonImmutable $a, CarbonImmutable $b): int => $a->timestamp <=> $b->timestamp
         );
 
         return $translatedHolidays;
diff --git a/src/Countries/Czechia.php b/src/Countries/Czechia.php
index 402aed2d..59786ed8 100644
--- a/src/Countries/Czechia.php
+++ b/src/Countries/Czechia.php
@@ -43,9 +43,9 @@ protected function allHolidays(int $year): array
         ];
 
         $filteredHolidays = array_map(
-            static fn (array $holiday) => $holiday[0],
+            static fn (array $holiday): string => $holiday[0],
             array_filter($holidays,
-                static fn (array $holiday) => $holiday[1] === true
+                static fn (array $holiday): bool => $holiday[1] === true
             )
         );
 
@@ -63,9 +63,9 @@ protected function variableHolidays(int $year): array
         ];
 
         return array_map(
-            static fn (array $variableHoliday) => $variableHoliday[0],
+            static fn (array $variableHoliday): \Carbon\CarbonImmutable => $variableHoliday[0],
             array_filter($variableHolidays,
-                static fn (array $variableHoliday) => $variableHoliday[1] === true
+                static fn (array $variableHoliday): bool => $variableHoliday[1] === true
             )
         );
     }
diff --git a/src/Countries/Morocco.php b/src/Countries/Morocco.php
index 2d0ed9df..2b999263 100644
--- a/src/Countries/Morocco.php
+++ b/src/Countries/Morocco.php
@@ -139,7 +139,7 @@ private function islamicToGregorian(int $y, int $m, int $d): array
      * @param  float  $floatNum  The floating-point number to be rounded.
      * @return float The rounded integer value.
      */
-    private function intPart($floatNum)
+    private function intPart(int|float $floatNum): float
     {
         // Check if the floating-point number is negative
         if ($floatNum < -0.0000001) {
diff --git a/src/Countries/Norway.php b/src/Countries/Norway.php
index f2115d0c..c2091958 100644
--- a/src/Countries/Norway.php
+++ b/src/Countries/Norway.php
@@ -27,7 +27,7 @@ protected function variableHolidays(int $year): array
     {
         $easter = $this->easter($year);
 
-        $holidays = [
+        return [
             'Skjærtorsdag' => $easter->subDays(3),
             'Langfredag' => $easter->subDays(2),
             'Første påskedag' => $easter,
@@ -36,7 +36,5 @@ protected function variableHolidays(int $year): array
             'Første pinsedag' => $easter->addDays(49),
             'Andre pinsedag' => $easter->addDays(50),
         ];
-
-        return $holidays;
     }
 }
diff --git a/src/Countries/Switzerland.php b/src/Countries/Switzerland.php
index 60b3b688..e19004a7 100644
--- a/src/Countries/Switzerland.php
+++ b/src/Countries/Switzerland.php
@@ -335,7 +335,7 @@ public function regionalHolidays(int $year): array
 
         $regionalHolidays = array_filter(
             $regionallyDifferentHolidays,
-            fn ($key) => in_array($key, $currentRegion),
+            fn ($key): bool => in_array($key, $currentRegion),
             ARRAY_FILTER_USE_KEY
         );
 
diff --git a/src/Countries/Taiwan.php b/src/Countries/Taiwan.php
index 762c2c89..a2351e79 100644
--- a/src/Countries/Taiwan.php
+++ b/src/Countries/Taiwan.php
@@ -28,7 +28,7 @@ protected function allHolidays(int $year): array
     /** @return array<string, string> */
     protected function variableHolidays(int $year): array
     {
-        return array_filter(array_map(fn ($date) => $this->lunarCalendar($date, $year), [
+        return array_filter(array_map(fn ($date): ?string => $this->lunarCalendar($date, $year), [
             '農曆春節-正月初一' => '01-01',
             '農曆春節-正月初二' => '01-02',
             '農曆春節-正月初三' => '01-03',
diff --git a/src/Holidays.php b/src/Holidays.php
index 4f27a579..53617142 100755
--- a/src/Holidays.php
+++ b/src/Holidays.php
@@ -60,7 +60,7 @@ public function isHoliday(CarbonInterface|string $date, Country|string|null $cou
         $holidays = array_column($holidays, 'date');
 
         $formattedHolidays = array_map(
-            fn (string $holiday) => CarbonImmutable::parse($holiday)->format('Y-m-d'),
+            fn (string $holiday): string => CarbonImmutable::parse($holiday)->format('Y-m-d'),
             $holidays
         );