diff --git a/include/aidge/utils/TensorUtils.hpp b/include/aidge/utils/TensorUtils.hpp
index e287db4e8724f0388c13d438fc2e152fe69021cd..b5601f84c60b81d8c560b61b06c00673f51f4eee 100644
--- a/include/aidge/utils/TensorUtils.hpp
+++ b/include/aidge/utils/TensorUtils.hpp
@@ -44,6 +44,7 @@ bool approxEq(const Tensor& t1, const Tensor& t2, float relative = 1e-5f, float
     }
     for(size_t i = 0; i < t1.size(); ++i){
         if (static_cast<float>(std::abs(t1.get<T1>(i) - t2.get<T2>(i))) > (absolute + (relative * static_cast<float>(std::abs(t2.get<T2>(i)))))){
+            fmt::print("t1:\n{}\nt2\n{}\nat index {} {} != {}", t1, t2, i, t1.get<T1>(i), t2.get<T1>(i));
             return false;
         }
     }