diff --git a/opm/core/tof/TofReorder.cpp b/opm/core/tof/TofReorder.cpp
index 011d16a0c..ed63e5b4a 100644
--- a/opm/core/tof/TofReorder.cpp
+++ b/opm/core/tof/TofReorder.cpp
@@ -374,7 +374,7 @@ namespace Opm
                 // We have no contribution from face f, it is an outflow face.
                 continue;
             }
-            ASSERT(influx_f > 0.0);
+            assert(influx_f > 0.0);
             const double omega_star = influx_f/flux_face;
             // SPU
             // const double omega = 0.0;