diff --git a/basegraph.cpp b/basegraph.cpp
index 30d7e9fc..9196d78f 100644
--- a/basegraph.cpp
+++ b/basegraph.cpp
@@ -1387,6 +1387,7 @@ EX void initgraph() {
   loadConfig();
 #endif
   arcm::current.parse();
+  if(geometry == gProduct) geometry = product::underlying;
 
 #if CAP_COMMANDLINE
   arg::read(2);
diff --git a/config.cpp b/config.cpp
index 9d063911..efc0b3ed 100644
--- a/config.cpp
+++ b/config.cpp
@@ -511,6 +511,7 @@ EX void initConfig() {
   addsaver(models::use_atan, "use_atan");
   
   addsaver(arcm::current.symbol, "arcm-symbol", "4^5");
+  addsaverenum(product::underlying, "product-underlying");
   
   for(int i=0; i<isize(ginf); i++) {
     if(ginf[i].flags & qELLIPTIC)