diff --git a/optimum/exporters/onnx/base.py b/optimum/exporters/onnx/base.py
index ccf3a3f2bde..568535472fa 100644
--- a/optimum/exporters/onnx/base.py
+++ b/optimum/exporters/onnx/base.py
@@ -175,10 +175,10 @@ class OnnxConfig(ExportConfig, ABC):
         ),
         "reinforcement-learning": OrderedDict(
             {
-                "state_preds": {0: "batch_size", 1: "sequence_length"},
-                "action_preds": {0: "batch_size", 1: "sequence_length"},
-                "return_preds": {0: "batch_size", 1: "sequence_length"},
-                "last_hidden_state": {0: "batch_size", 1: "sequence_length"},
+                "state_preds": {0: "batch_size", 1: "sequence_length", 2: "states"},
+                "action_preds": {0: "batch_size", 1: "sequence_length", 2: "actions"},
+                "return_preds": {0: "batch_size", 1: "sequence_length", 2: "returns"},
+                "last_hidden_state": {0: "batch_size", 1: "sequence_length", 2: "last_hidden_state"},
             }
         ),
         "semantic-segmentation": OrderedDict({"logits": {0: "batch_size", 1: "num_labels", 2: "height", 3: "width"}}),
diff --git a/optimum/exporters/onnx/model_configs.py b/optimum/exporters/onnx/model_configs.py
index b2932079dd2..d31fef36cf5 100644
--- a/optimum/exporters/onnx/model_configs.py
+++ b/optimum/exporters/onnx/model_configs.py
@@ -18,6 +18,7 @@
 from typing import TYPE_CHECKING, Any, Dict, List, Literal, Optional, Tuple, Union
 
 from packaging import version
+from sipbuild.generator.parser.tokens import states
 from transformers.utils import is_tf_available
 
 from ...onnx import merge_decoders
@@ -264,16 +265,20 @@ class DecisionTransformerOnnxConfig(GPT2OnnxConfig):
 
     @property
     def inputs(self) -> Dict[str, Dict[int, str]]:
-        dynamic_axis = {0: "batch_size", 1: "sequence_length"}
+        DEFAULT_DUMMY_SHAPES['actions'] = self._normalized_config.config.act_dim
+        DEFAULT_DUMMY_SHAPES['states'] = self._normalized_config.config.state_dim
+        DEFAULT_DUMMY_SHAPES['returns'] = 1
+        DEFAULT_DUMMY_SHAPES['last_hidden_state'] = self._normalized_config.config.hidden_size
 
         return {
-            'actions': dynamic_axis,
-            'timesteps': dynamic_axis,
-            'attention_mask': dynamic_axis,
-            'returns_to_go': dynamic_axis,
-            'states': dynamic_axis,
+            'states': {0: 'batch_size', 1: 'sequence_length', 2: 'states'},
+            'actions': {0: 'batch_size', 1: 'sequence_length', 2: 'actions'},
+            'returns_to_go': {0: 'batch_size', 1: 'sequence_length', 2: 'returns'},
+            'timesteps': {0: 'batch_size', 1: 'sequence_length'},
+            'attention_mask': {0: 'batch_size', 1: 'sequence_length'},
         }
 
+
 class GPTNeoOnnxConfig(TextDecoderWithPositionIdsOnnxConfig):
     DEFAULT_ONNX_OPSET = 14
     NORMALIZED_CONFIG_CLASS = NormalizedTextConfig.with_args(num_attention_heads="num_heads")
diff --git a/optimum/utils/input_generators.py b/optimum/utils/input_generators.py
index e6f2059a1fc..808213eee10 100644
--- a/optimum/utils/input_generators.py
+++ b/optimum/utils/input_generators.py
@@ -522,20 +522,24 @@ class DummyDecisionTransformerInputGenerator(DummyTextInputGenerator):
 
     def generate(self, input_name: str, framework: str = "pt", int_dtype: str = "int64", float_dtype: str = "fp32"):
 
+        states = self.normalized_config.config.state_dim
+        actions = self.normalized_config.config.act_dim
+        max_ep_len = self.normalized_config.config.max_ep_len
+
         if input_name == "states":
-            shape = [self.batch_size, self.normalized_config.config.state_dim]
+            shape = [self.batch_size, self.sequence_length, states]
         elif input_name == "actions":
-            shape = [self.batch_size, self.normalized_config.config.act_dim]
+            shape = [self.batch_size, self.sequence_length, actions]
         elif input_name == 'returns_to_go':
-            shape = [self.batch_size, 1]
+            shape = [self.batch_size, self.sequence_length, 1]
         elif input_name == 'timesteps':
-            shape = [self.normalized_config.config.state_dim, self.batch_size]
-            max_value = self.normalized_config.config.max_ep_len
+            shape = [self.batch_size, self.sequence_length]
+            max_value = max_ep_len
             return self.random_int_tensor(shape=shape, max_value = max_value, framework=framework, dtype=int_dtype)
         elif input_name == "attention_mask":
-            shape = [self.batch_size, self.normalized_config.config.state_dim]
+            shape = [self.batch_size, self.sequence_length]
 
-        return self.random_float_tensor(shape, min_value=-1., max_value=1., framework=framework, dtype=float_dtype)
+        return self.random_float_tensor(shape, min_value=-2., max_value=2., framework=framework, dtype=float_dtype)
 
 
 class DummySeq2SeqDecoderTextInputGenerator(DummyDecoderTextInputGenerator):