1 files changed, 3 insertions, 2 deletions
diff --git a/tests/sendmail/driver.cxx b/tests/sendmail/driver.cxx
index e73940b..a29650c 100644
--- a/tests/sendmail/driver.cxx
+++ b/tests/sendmail/driver.cxx
@@ -1,8 +1,6 @@
 // file      : tests/sendmail/driver.cxx -*- C++ -*-
 // license   : MIT; see accompanying LICENSE file
 
-#include <cassert>
-
 #ifndef __cpp_lib_modules_ts
 #include <iostream>
 #include <system_error>
@@ -30,6 +28,9 @@ import butl.small_vector; // @@ MOD Clang should not be necessary.
 #include <libbutl/sendmail.mxx>
 #endif
 
+#undef NDEBUG
+#include <cassert>
+
 using namespace std;
 using namespace butl;