diff --git a/include/ircd/simd/print.h b/include/ircd/simd/print.h
index b7d653c69..1a2dfe49d 100644
--- a/include/ircd/simd/print.h
+++ b/include/ircd/simd/print.h
@@ -49,7 +49,7 @@ namespace ircd::simd
 	/// One of the other functions in this suite must be selected by this
 	/// template to generate the desired string.
 	template<class T,
-	         class F>
+	         class F = decltype(print_mem<T>)>
 	bool
 	print(const T,
 	      F&& printer      = print_mem<T>,