diff --git a/include/bmat8_impl.hpp b/include/bmat8_impl.hpp
index 22177a69..54f2ef4e 100644
--- a/include/bmat8_impl.hpp
+++ b/include/bmat8_impl.hpp
@@ -402,7 +402,8 @@ inline size_t BMat8::nr_rows() const {
     return _mm_popcnt_u64(_mm_movemask_epi8(x != epu8 {}));
 }
 
-constexpr Perm16 rev8 (epu8 {7,6,5,4,3,2,1,0,8,9,10,11,12,13,14,15});
+static HPCOMBI_CONSTEXPR Perm16
+  rev8 (epu8 {7,6,5,4,3,2,1,0,8,9,10,11,12,13,14,15});
 inline BMat8 BMat8::row_permuted(Perm16 p) const {
     epu8 x = _mm_set_epi64x(0, _data);
     x = permuted(x, rev8);