diff --git a/unit_tests/operator/Test_ExpandImpl.cpp b/unit_tests/operator/Test_ExpandImpl.cpp
index 3fcb5e4460388712abb99dc4aa2f1fd0f274d841..98661080dc5a0cfdfa4a8400fa8e20de879bdda7 100644
--- a/unit_tests/operator/Test_ExpandImpl.cpp
+++ b/unit_tests/operator/Test_ExpandImpl.cpp
@@ -29,7 +29,7 @@ using std::shared_ptr;
 
 using namespace Aidge;
 
-void setupTestExpand(shared_ptr<Tensor> inputData,
+static void setupTestExpand(shared_ptr<Tensor> inputData,
                      shared_ptr<Tensor> inputShape,
                      shared_ptr<OperatorTensor> &op,
                      shared_ptr<Tensor> &expectedOutput) {