diff --git a/coord/base.hpp b/coord/base.hpp
index 4890e686..efbf83b3 100644
--- a/coord/base.hpp
+++ b/coord/base.hpp
@@ -66,7 +66,7 @@ namespace util::coord {
         base () = default;
 
         /// constructs an instance where all elements are initialised to `val'.
-        constexpr explicit
+        constexpr
         base (T fill)
         {
             for (decltype(S) i = 0; i < S; ++i)