diff --git a/src/Symfony/Component/Workflow/Dumper/PlantUmlDumper.php b/src/Symfony/Component/Workflow/Dumper/PlantUmlDumper.php
index 1b9b5f522bed2..f6b2536372019 100644
--- a/src/Symfony/Component/Workflow/Dumper/PlantUmlDumper.php
+++ b/src/Symfony/Component/Workflow/Dumper/PlantUmlDumper.php
@@ -237,7 +237,7 @@ private function getTransitionEscapedWithStyle(MetadataStoreInterface $workflowM
     private function getTransitionColor(string $color): string
     {
         // PUML format requires that color in transition have to be prefixed with “#”.
-        if ('#' !== substr($color, 0, 1)) {
+        if (!str_starts_with($color, '#')) {
             $color = '#'.$color;
         }