diff --git a/include/tim/experimental/trace/README.md b/include/tim/experimental/trace/README.md
index dd25bbe..8830e31 100755
--- a/include/tim/experimental/trace/README.md
+++ b/include/tim/experimental/trace/README.md
@@ -35,7 +35,7 @@ struct TensorSpec {
 
   TensorSpec& SetDataType(DataType datatype);
 
-  TensorSpec& SetShape(ShapeType& shape);
+  TensorSpec& SetShape(const ShapeType& shape);
 
   TensorSpec& SetAttribute(TensorAttribute attr);
   ...
diff --git a/include/tim/vx/tensor.h b/include/tim/vx/tensor.h
index 4e4b236..0d26d7a 100644
--- a/include/tim/vx/tensor.h
+++ b/include/tim/vx/tensor.h
@@ -106,7 +106,7 @@ struct TensorSpec {
 
   TensorSpec& SetDataType(DataType datatype);
 
-  TensorSpec& SetShape(ShapeType& shape);
+  TensorSpec& SetShape(const ShapeType& shape);
 
   TensorSpec& SetAttribute(TensorAttribute attr);
 
diff --git a/include/tim/vx/types.h b/include/tim/vx/types.h
index 432ff1c..7418fd4 100644
--- a/include/tim/vx/types.h
+++ b/include/tim/vx/types.h
@@ -29,8 +29,6 @@ namespace vx {
 
 enum class DataType {
   UNKNOWN,
-  INT4,
-  UINT4,
   INT8,
   UINT8,
   INT16,
@@ -40,7 +38,9 @@ enum class DataType {
   INT64,
   FLOAT16,
   FLOAT32,
-  BOOL8
+  BOOL8,
+  INT4,
+  UINT4
 };
 
 enum class QuantType { NONE, ASYMMETRIC, SYMMETRIC_PER_CHANNEL, DYNAMIC_FIXED_POINT };
diff --git a/src/tim/vx/tensor.cc b/src/tim/vx/tensor.cc
index 3fcd246..e424843 100644
--- a/src/tim/vx/tensor.cc
+++ b/src/tim/vx/tensor.cc
@@ -401,7 +401,7 @@ TensorSpec& TensorSpec::SetDataType(DataType datatype) {
   return *this;
 }
 
-TensorSpec& TensorSpec::SetShape(ShapeType& shape) {
+TensorSpec& TensorSpec::SetShape(const ShapeType& shape) {
   this->shape_ = shape;
   return *this;
 }