diff --git a/backends/apple/mps/operators/constant_ops.py b/backends/apple/mps/operators/constant_ops.py
index aa92258da86..dacb09215cb 100644
--- a/backends/apple/mps/operators/constant_ops.py
+++ b/backends/apple/mps/operators/constant_ops.py
@@ -55,7 +55,12 @@ def define_node(
         elif node.target == exir_ops.edge.aten.empty.memory_format:
             fill_value = 0
         elif node.target == exir_ops.edge.aten.scalar_tensor.default:
-            fill_value = float(node.args[0])
+            fill_value = cast(float, node.args[0])
+
+        if fill_value == float("-inf"):
+            fill_value = "-inf"
+        elif fill_value == float("inf"):
+            fill_value = "inf"
 
         dtype = MPSDataType.mps_data_type_float32
         if node.kwargs and "dtype" in node.kwargs and node.kwargs["dtype"] is not None:
diff --git a/backends/apple/mps/operators/node_visitor.py b/backends/apple/mps/operators/node_visitor.py
index ed2afea7727..e9f879db88a 100644
--- a/backends/apple/mps/operators/node_visitor.py
+++ b/backends/apple/mps/operators/node_visitor.py
@@ -157,10 +157,9 @@ def define_scalar(
         """
         assert isinstance(val, int) or isinstance(val, float)
 
-        if val in self.tensor_to_id:
-            return self.tensor_to_id[val]
+        id = len(mps_graph.mps_values)
+        self.tensor_to_id[val] = id
 
-        id = self.get_serialized_id(val, mps_graph)
         tensor = torch.tensor(val)
         constant_buffer_size, constant_buffer, mps_data_type = self.get_serialized_data(
             tensor, mps_graph, mps_data_type, id
diff --git a/backends/apple/mps/serialization/mps_graph_schema.py b/backends/apple/mps/serialization/mps_graph_schema.py
index 04a41abaa1c..66697b04b7d 100644
--- a/backends/apple/mps/serialization/mps_graph_schema.py
+++ b/backends/apple/mps/serialization/mps_graph_schema.py
@@ -391,7 +391,7 @@ class MPSFull:
 
 @dataclass
 class MPSFullLike(MPSNode1x1):
-    fill_value: float = 0.0
+    fill_value: Union[float, str] = 0.0
     dtype: MPSDataType = MPSDataType.mps_data_type_float32