--- a/lib.c
+++ b/lib.c
@@ -1438,7 +1438,7 @@ uc_printf_common(uc_vm_t *vm, size_t nar
 
 			switch (t) {
 			case UC_INTEGER:
-				ucv_stringbuf_printf(buf, sfmt, arg.n);
+				ucv_stringbuf_printf(buf, sfmt, (int)arg.n);
 				break;
 
 			case UC_DOUBLE: