diff --git a/src/Pbc.cpp b/src/Pbc.cpp
index 42e94d011a742c547a2436a97fdc492b15dbc517..7f7485e29b2c435e610631702382ce2d067942d4 100644
--- a/src/Pbc.cpp
+++ b/src/Pbc.cpp
@@ -16,6 +16,9 @@ void Pbc::setBox(const Tensor&b){
 // UP TO NOW ONLY WORKS WITH ORTHOROMIBIC (should implement matrix inversion)
 // detect type:
   const double epsilon=1e-14;
+
+  if(box.determinant()<epsilon)return;
+
   bool cxy=false;
   bool cxz=false;
   bool cyz=false;