diff --git a/OutputShapeUtils.hpp b/OutputShapeUtils.hpp
index d1818db..be255c2 100644
--- a/OutputShapeUtils.hpp
+++ b/OutputShapeUtils.hpp
@@ -17,6 +17,8 @@
 
 armnn::TensorShape InferPreluOutputShape(const armnn::TensorShape& inputShape, const armnn::TensorShape& alphaShape);
 
+armnn::TensorShape InferSubOutputShape(const armnn::TensorShape& input0Shape, const armnn::TensorShape& input1Shape);
+
 } // namespace armnn_driver