diff --git a/src/main/java/jakarta/validation/Validation.java b/src/main/java/jakarta/validation/Validation.java
index 9823aa91..7244d1dc 100644
--- a/src/main/java/jakarta/validation/Validation.java
+++ b/src/main/java/jakarta/validation/Validation.java
@@ -383,7 +383,7 @@ private synchronized List<ValidationProvider<?>> getCachedValidationProviders(Cl
 		}
 
 		private synchronized void cacheValidationProviders(ClassLoader classLoader, List<ValidationProvider<?>> providers) {
-			providersPerClassloader.put( classLoader, new SoftReference<>( providers ) );
+			providersPerClassloader.put( classLoader, new SoftReference<>( List.copyOf(  providers ) ) );
 		}
 	}
 }