diff --git a/.php-cs-fixer.php b/.php-cs-fixer.php
index def17ee..cc0b1c4 100644
--- a/.php-cs-fixer.php
+++ b/.php-cs-fixer.php
@@ -18,15 +18,15 @@
     __DIR__ . '/LICENSE.md',
     License\Range::since(
         License\Year::fromString('2018'),
-        new \DateTimeZone('UTC')
+        new \DateTimeZone('UTC'),
     ),
     License\Holder::fromString('Andreas Möller'),
-    License\Url::fromString('https://github.com/ergebnis/json-printer')
+    License\Url::fromString('https://github.com/ergebnis/json-printer'),
 );
 
 $license->save();
 
-$config = PhpCsFixer\Config\Factory::fromRuleSet(new PhpCsFixer\Config\RuleSet\Php72($license->header()), [
+$config = PhpCsFixer\Config\Factory::fromRuleSet(new PhpCsFixer\Config\RuleSet\Php73($license->header()), [
     'escape_implicit_backslashes' => false,
     'mb_str_functions' => false,
 ]);
diff --git a/src/Printer.php b/src/Printer.php
index 5b856ba..897aac0 100644
--- a/src/Printer.php
+++ b/src/Printer.php
@@ -41,21 +41,21 @@ public function print(string $json, string $indent = '    ', string $newLine = \
         if (null === \json_decode($json) && \JSON_ERROR_NONE !== \json_last_error()) {
             throw new \InvalidArgumentException(\sprintf(
                 '"%s" is not valid JSON.',
-                $json
+                $json,
             ));
         }
 
         if (1 !== \preg_match('/^( +|\t+)$/', $indent)) {
             throw new \InvalidArgumentException(\sprintf(
                 '"%s" is not a valid indent.',
-                $indent
+                $indent,
             ));
         }
 
         if (1 !== \preg_match('/^(?>\r\n|\n|\r)$/', $newLine)) {
             throw new \InvalidArgumentException(\sprintf(
                 '"%s" is not a valid new-line character sequence.',
-                $newLine
+                $newLine,
             ));
         }
 
diff --git a/test/Unit/PrinterTest.php b/test/Unit/PrinterTest.php
index 82f5e0e..1607442 100644
--- a/test/Unit/PrinterTest.php
+++ b/test/Unit/PrinterTest.php
@@ -41,7 +41,7 @@ public function testPrintRejectsInvalidJson(): void
         $this->expectException(\InvalidArgumentException::class);
         $this->expectExceptionMessage(\sprintf(
             '"%s" is not valid JSON.',
-            $json
+            $json,
         ));
 
         $printer->print($json);
@@ -61,12 +61,12 @@ public function testPrintRejectsInvalidIndent(string $indent): void
         $this->expectException(\InvalidArgumentException::class);
         $this->expectExceptionMessage(\sprintf(
             '"%s" is not a valid indent.',
-            $indent
+            $indent,
         ));
 
         $printer->print(
             $json,
-            $indent
+            $indent,
         );
     }
 
@@ -103,13 +103,13 @@ public function testPrintRejectsInvalidNewLine(string $newLine): void
         $this->expectException(\InvalidArgumentException::class);
         $this->expectExceptionMessage(\sprintf(
             '"%s" is not a valid new-line character sequence.',
-            $newLine
+            $newLine,
         ));
 
         $printer->print(
             $json,
             $indent,
-            $newLine
+            $newLine,
         );
     }
 
@@ -184,7 +184,7 @@ public function testPrintPrintsPrettyWithIndent(): void
 
         $printed = $printer->print(
             $json,
-            $indent
+            $indent,
         );
 
         self::assertSame($expected, $printed);
@@ -215,7 +215,7 @@ public function testPrintPrintsPrettyWithIndentAndNewLine(string $newLine): void
         $expectedWithNewLine = \str_replace(
             \PHP_EOL,
             $newLine,
-            $expected
+            $expected,
         );
 
         $printer = new Printer();
@@ -223,7 +223,7 @@ public function testPrintPrintsPrettyWithIndentAndNewLine(string $newLine): void
         $printed = $printer->print(
             $json,
             $indent,
-            $newLine
+            $newLine,
         );
 
         self::assertSame($expectedWithNewLine, $printed);