diff --git a/src/Native/include/nncase/runtime/simple_types.h b/src/Native/include/nncase/runtime/simple_types.h
index 62ef5e080d..cebc780376 100644
--- a/src/Native/include/nncase/runtime/simple_types.h
+++ b/src/Native/include/nncase/runtime/simple_types.h
@@ -127,7 +127,6 @@ using dims_t = itlib::small_vector<size_t, 8>;
 using axes_t = itlib::small_vector<int64_t, 8>;
 using strides_t = itlib::small_vector<size_t, 8>;
 using paddings_t = itlib::small_vector<padding, 4>;
-using slope_t = itlib::small_vector<float_t, 4>;
 
 template <class... Ints>
 auto fixed_dims(Ints &&...values) -> std::array<size_t, sizeof...(Ints)> {
diff --git a/tests/kernels/test_prelu.cpp b/tests/kernels/test_prelu.cpp
index 2d4f89ec7d..eeea7b4d24 100644
--- a/tests/kernels/test_prelu.cpp
+++ b/tests/kernels/test_prelu.cpp
@@ -25,6 +25,7 @@
 using namespace nncase;
 using namespace nncase::runtime;
 using namespace ortki;
+using slope_t = itlib::small_vector<float_t, 4>;
 
 class PreluTest : public KernelTest,
                   public ::testing::TestWithParam<