diff --git a/config/.php_cs.dist.php b/config/.php_cs.dist.php
index e6b74160..778a2352 100644
--- a/config/.php_cs.dist.php
+++ b/config/.php_cs.dist.php
@@ -76,5 +76,6 @@
         'phpdoc_trim_consecutive_blank_line_separation' => true,
         'no_empty_statement' => true,
         'semicolon_after_instruction' => true,
+        'nullable_type_declaration_for_default_null_value' => true,
     ])
     ;
diff --git a/src/Psl/Vec/range.php b/src/Psl/Vec/range.php
index 6c937db8..59b1e79a 100644
--- a/src/Psl/Vec/range.php
+++ b/src/Psl/Vec/range.php
@@ -45,7 +45,7 @@
  *
  * @see https://github.com/vimeo/psalm/issues/2152#issuecomment-533363310
  */
-function range(int|float $start, int|float $end, int|float $step = null): array
+function range(int|float $start, int|float $end, int|float|null $step = null): array
 {
     if ((float) $start === (float) $end) {
         return [$start];
diff --git a/tests/unit/Dict/SliceTest.php b/tests/unit/Dict/SliceTest.php
index 46665de9..bdbe2fd3 100644
--- a/tests/unit/Dict/SliceTest.php
+++ b/tests/unit/Dict/SliceTest.php
@@ -12,7 +12,7 @@ final class SliceTest extends TestCase
     /**
      * @dataProvider provideData
      */
-    public function testSlice(array $expected, array $array, int $n, int $l = null): void
+    public function testSlice(array $expected, array $array, int $n, ?int $l = null): void
     {
         $result = Dict\slice($array, $n, $l);
 
diff --git a/tests/unit/Regex/EveryMatchTest.php b/tests/unit/Regex/EveryMatchTest.php
index f0db03ad..f8559cf9 100644
--- a/tests/unit/Regex/EveryMatchTest.php
+++ b/tests/unit/Regex/EveryMatchTest.php
@@ -19,7 +19,7 @@ public function testMatching(
         array $expected,
         string $subject,
         string $pattern,
-        TypeInterface $shape = null,
+        ?TypeInterface $shape = null,
         int $offset = 0
     ): void {
         static::assertSame($expected, Regex\every_match($subject, $pattern, $shape, $offset));
diff --git a/tests/unit/Regex/FirstMatchTest.php b/tests/unit/Regex/FirstMatchTest.php
index 79d35d6d..b0bca838 100644
--- a/tests/unit/Regex/FirstMatchTest.php
+++ b/tests/unit/Regex/FirstMatchTest.php
@@ -19,7 +19,7 @@ public function testMatching(
         array $expected,
         string $subject,
         string $pattern,
-        TypeInterface $shape = null,
+        ?TypeInterface $shape = null,
         int $offset = 0
     ): void {
         static::assertSame($expected, Regex\first_match($subject, $pattern, $shape, $offset));
diff --git a/tests/unit/Vec/SliceTest.php b/tests/unit/Vec/SliceTest.php
index eef39c9b..d0d0090a 100644
--- a/tests/unit/Vec/SliceTest.php
+++ b/tests/unit/Vec/SliceTest.php
@@ -12,7 +12,7 @@ final class SliceTest extends TestCase
     /**
      * @dataProvider provideData
      */
-    public function testSlice(array $expected, array $array, int $n, int $l = null): void
+    public function testSlice(array $expected, array $array, int $n, ?int $l = null): void
     {
         $result = Vec\slice($array, $n, $l);