diff --git a/src/transformers/training_args_seq2seq.py b/src/transformers/training_args_seq2seq.py
index 19e1ff1b2d2..ccacbbb3702 100644
--- a/src/transformers/training_args_seq2seq.py
+++ b/src/transformers/training_args_seq2seq.py
@@ -83,3 +83,15 @@ class Seq2SeqTrainingArguments(TrainingArguments):
             "help": "Model id, file path or url pointing to a GenerationConfig json file, to use during prediction."
         },
     )
+
+    def to_dict(self):
+        """
+        Serializes this instance while replace `Enum` by their values and `GenerationConfig` by dictionaries (for JSON
+        serialization support). It obfuscates the token values by removing their value.
+        """
+        # filter out fields that are defined as field(init=False)
+        d = super().to_dict()
+        for k, v in d.items():
+            if isinstance(v, GenerationConfig):
+                d[k] = v.to_dict()
+        return d