--- a/ucx/szmul.c	Fri Jan 03 21:40:57 2025 +0100
+++ b/ucx/szmul.c	Sat Jan 04 13:03:01 2025 +0100
@@ -26,6 +26,9 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "cx/common.h"
+
+#ifndef CX_SZMUL_BUILTIN
 int cx_szmul_impl(
         size_t a,
         size_t b,
@@ -44,3 +47,4 @@
         return 1;
     }
 }
+#endif // CX_SZMUL_BUILTIN