diff --git a/src/Twig/Component/Badge.php b/src/Twig/Component/Badge.php
index d6a208c..300a126 100644
--- a/src/Twig/Component/Badge.php
+++ b/src/Twig/Component/Badge.php
@@ -48,7 +48,7 @@ final class Badge
 
             if (!in_array($colour, $cases)) {
                 $formattedCases = implode(', ', array_map(fn (string $s) => '"'.$s.'"', $cases));
-                throw new \RuntimeException(sprintf('"%s" is not a valid Badge colour. Available options are: %s', $colour, $formattedCases));
+                throw new \RuntimeException(sprintf('"%s" is not a valid badge colour. Available options are: %s.', $colour, $formattedCases));
             }
 
             $colour  = strtoupper($colour);