diff --git a/test/first_aligned.cpp b/test/first_aligned.cpp
index f00ed57a5..5fb806298 100644
--- a/test/first_aligned.cpp
+++ b/test/first_aligned.cpp
@@ -34,6 +34,9 @@ void test_first_aligned_helper(Scalar *array, int size)
 template<typename Scalar>
 void test_none_aligned_helper(Scalar *array, int size)
 {
+  // Suppress 'unreferenced formal parameter's warnings.
+  (void)array;
+  (void)size;
   VERIFY(ei_packet_traits<Scalar>::size == 1 || ei_first_aligned(array, size) == size);
 }