diff --git a/include/llama/ArrayExtents.hpp b/include/llama/ArrayExtents.hpp
index 5e3431decb..33cfe6216e 100644
--- a/include/llama/ArrayExtents.hpp
+++ b/include/llama/ArrayExtents.hpp
@@ -126,6 +126,7 @@ namespace llama
     static_assert(std::is_trivially_move_constructible_v<ArrayExtents<1>>);
     static_assert(std::is_trivially_copy_assignable_v<ArrayExtents<1>>);
     static_assert(std::is_trivially_move_assignable_v<ArrayExtents<1>>);
+    static_assert(std::is_empty_v<ArrayExtents<1>>);
 
     template<std::size_t... SizesA, std::size_t... SizesB>
     LLAMA_FN_HOST_ACC_INLINE constexpr auto operator==(ArrayExtents<SizesA...> a, ArrayExtents<SizesB...> b) -> bool
diff --git a/tests/virtualrecord.cpp b/tests/virtualrecord.cpp
index 8a7a361163..bff7fa1610 100644
--- a/tests/virtualrecord.cpp
+++ b/tests/virtualrecord.cpp
@@ -962,12 +962,7 @@ TEST_CASE("VirtualRecord.One.size")
 {
     using Mapping = llama::mapping::MinAlignedOne<llama::ArrayExtents<>, Particle>;
     STATIC_REQUIRE(Mapping{}.blobSize(0) == 56);
-
-    struct S : Mapping::ArrayIndex
-    {
-        char c;
-    };
-    STATIC_REQUIRE(sizeof(S) == sizeof(char));
+    STATIC_REQUIRE(std::is_empty_v<Mapping::ArrayIndex>);
 
     [[maybe_unused]] const auto v = llama::allocViewStack<0, Particle>();
     STATIC_REQUIRE(std::is_same_v<typename decltype(v)::Mapping, Mapping>);