diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 6f878d9..bda3a2e 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -61,7 +61,7 @@ class Configuration implements ConfigurationInterface
                     ->end()
 
                     ->arrayPrototype()
-                        ->normalizeKeys(false)
+                        ->normalizeKeys(false) # Don't normalize hyphens into underscores etc
                         ->children()
                             ->scalarNode('fill')->isRequired()->end()
                             ->scalarNode('stroke')->isRequired()->end()