diff --git a/python/pyarmnn/test/test_runtime.py b/python/pyarmnn/test/test_runtime.py
index fbdd804..e558e84 100644
--- a/python/pyarmnn/test/test_runtime.py
+++ b/python/pyarmnn/test/test_runtime.py
@@ -27,6 +27,7 @@
     input_tensor_id = input_binding_info[0]
 
     input_tensor_info = input_binding_info[1]
+    input_tensor_info.SetConstant()
 
     output_names = parser.GetSubgraphOutputTensorNames(graph_id)