diff --git a/Sources/UnitTesting/CodeCompletExceptionUT.cs b/Sources/UnitTesting/CodeCompletExceptionUT.cs
index 5982a14..cafd51a 100644
--- a/Sources/UnitTesting/CodeCompletExceptionUT.cs
+++ b/Sources/UnitTesting/CodeCompletExceptionUT.cs
@@ -58,13 +58,16 @@ namespace UnitTesting
         {
             CodeCompletException exception = new CodeCompletException();
 
+            #pragma warning disable SYSLIB0050
+            SerializationInfo info = new SerializationInfo(typeof(CodeCompletException), new FormatterConverter());
+            StreamingContext contexte = new StreamingContext(StreamingContextStates.All);
+            #pragma warning restore SYSLIB0050
 
-            string jsonString = JsonSerializer.Serialize(exception);
-            CodeCompletException? exceptionSerialisee = 
-                JsonSerializer.Deserialize<CodeCompletException>(jsonString);
+            #pragma warning disable SYSLIB0051
+            exception.GetObjectData(info, contexte);
+            #pragma warning restore SYSLIB0051
 
-            Assert.NotNull(exceptionSerialisee);
-            Assert.Equal(exception.Message, exceptionSerialisee.Message);
+            Assert.Equal(exception.Message, info.GetString("Message"));
         }
     }
 }