diff --git a/hyper.h b/hyper.h
index 5af7bd56..037e419a 100644
--- a/hyper.h
+++ b/hyper.h
@@ -1472,7 +1472,7 @@ bool isAlchAny(eWall w);
 bool isAlchAny(cell *c);
 
 #define YDIST 101
-#define MODECODES 255
+#define MODECODES (1ll<<61)
   
 extern cellwalker cwt; // player character position
 
@@ -1481,7 +1481,7 @@ extern array<int, motypes> kills;
 
 extern int explore[10], exploreland[10][landtypes], landcount[landtypes];
 
-typedef int modecode_t;
+typedef flagtype modecode_t;
 extern map<modecode_t, array<int, ittypes> > hiitems;
 
 extern eLand firstland, specialland;
@@ -3832,7 +3832,7 @@ enum eOrbLandRelation {
 namespace torusconfig {
   extern int sdx, sdy;
   
-  enum eTorusMode { 
+  enum eTorusMode : char { 
     tmSingleHex, 
     tmSingle, 
     tmSlantedHex, 
diff --git a/yendor.cpp b/yendor.cpp
index c6404ecc..dff60b1f 100644
--- a/yendor.cpp
+++ b/yendor.cpp
@@ -955,6 +955,31 @@ int modecode() {
     mct += irr::density_code() << 21; // 8 bits
     }
   
+  // 32 bits [29..61) for geometry specifics
+  if(torus) {
+    mct += ll(torusconfig::dx) << 29;
+    mct += ll(torusconfig::dy) << 37;
+    mct += ll(torusconfig::qty) << 45;
+    mct += ll(torusconfig::torusmode) << 53;
+    }
+  
+  if(geometry == gQuotient) {
+    mct += ll(current_extra) << 29;
+    mct += ll(fgeomextras[current_extra].current_prime_id) << 37;
+    }
+  
+  if(geometry == gCrystal) {
+    mct += ll(ginf[geometry].sides) << 29;
+    mct += ll(ginf[geometry].vertices) << 37;
+    }
+  
+  if(geometry == gArchimedean) {
+    unsigned res = 7;
+    for(char c: arcm::current.symbol) res = res * 157 + c;
+    mct += ll(res) << 29;
+    if(PURE) mct ^= (1<<29);
+    }
+  
   return mct;
   }