diff --git a/tests/test_TinyVector.cpp b/tests/test_TinyVector.cpp
index 5b9612d345e59e0ad1e6641df1dcb4dbbbceeae9..e61942a7fdc15c99b801c2f6bf6f6b10d260a530 100644
--- a/tests/test_TinyVector.cpp
+++ b/tests/test_TinyVector.cpp
@@ -47,6 +47,9 @@ TEST_CASE("TinyVector", "[algebra]") {
 
   REQUIRE(Catch::Detail::stringify(x) == "(3,2,4)");
 
-  // REQUIRE_THROWS(x[4]);
-  // REQUIRE_THROWS(x[-1]);
+#ifndef NDEBUG
+  REQUIRE_THROWS_AS(x[4]=0, AssertError);
+  const TinyVector<3,int>& const_x = x;
+  REQUIRE_THROWS_AS(const_x[-1], AssertError);
+#endif // NDEBUG
 }