Fix a missing include file.

diff --git a/tests/simplex/orientation_02.cc b/tests/simplex/orientation_02.cc
index 8931b1da8fd3aa5330b9a5ec1eaef8023f250c18..5154db626cb59b751bbb1163563748d86ce70123 100644 (file)
--- a/tests/simplex/orientation_02.cc
+++ b/tests/simplex/orientation_02.cc
@@ -17,6 +17,7 @@
 
 // Test a mesh with two tetrahedra for all possible orientations.
 
+#include <deal.II/grid/grid_generator.h>
 #include <deal.II/grid/reference_cell.h>
 #include <deal.II/grid/tria.h>