diff --git a/src/harmonicmaps.cc b/src/harmonicmaps.cc
index 02a99c3620a44168e0a82cce876284a6a10b32ec..d4e1511302a3e320f9655226377f3625bdc57074 100644
--- a/src/harmonicmaps.cc
+++ b/src/harmonicmaps.cc
@@ -133,7 +133,7 @@ int main (int argc, char *argv[])
 #if HAVE_DUNE_FOAMGRID
     typedef std::conditional<dim==1 or dim!=dimworld,FoamGrid<dim,dimworld>,UGGrid<dim> >::type GridType;
 #else
-    static_assert(dim!=dimworld, "You need to have dune-foamgrid installed for dim != dimworld!");
+    static_assert(dim==dimworld, "You need to have dune-foamgrid installed for dim != dimworld!");
     typedef std::conditional<dim==1,OneDGrid<dim>,UGGrid<dim> >::type GridType;
 #endif