diff --git a/embeddings.cpp b/embeddings.cpp
index 43f94d33..6c1f87f9 100644
--- a/embeddings.cpp
+++ b/embeddings.cpp
@@ -1275,6 +1275,7 @@ geom3::eSpatialEmbedding embed_by_name(string ss) {
   return seNone;
   }
 
-auto ah_embed = arg::add2("-seo", [] { arg::shift(); invoke_embed(embed_by_name(arg::args())); });
+auto ah_embed = arg::add2("-seo", [] { arg::shift(); invoke_embed(embed_by_name(arg::args())); })
+  + arg::add2("-never-invert", [] { never_invert = true; });
 
 }
diff --git a/geometry2.cpp b/geometry2.cpp
index 44bb5021..5af54875 100644
--- a/geometry2.cpp
+++ b/geometry2.cpp
@@ -450,7 +450,9 @@ EX bool no_easy_spin() {
   return NONSTDVAR || arcm::in() || WDIM == 3 || bt::in() || kite::in();
   }
 
-EX bool dont_inverse() { return PURE && cgi.emb->is_euc_in_noniso(); }
+EX bool never_invert;
+
+EX bool dont_inverse() { return never_invert || (PURE && cgi.emb->is_euc_in_noniso()); }
 
 ld hrmap_standard::spin_angle(cell *c, int d) {
   if(WDIM == 3) return SPIN_NOT_AVAILABLE;