diff --git a/backends/functional/cxx.cc b/backends/functional/cxx.cc
index 46ce88bd62c..d105c4aa720 100644
--- a/backends/functional/cxx.cc
+++ b/backends/functional/cxx.cc
@@ -17,6 +17,8 @@
  *
  */
 
+#include <cassert>
+#include <array>
 #include "kernel/yosys.h"
 #include "kernel/drivertools.h"
 #include "kernel/topo_scc.h"