diff --git a/goldberg.cpp b/goldberg.cpp
index 8bd22e5a..f065c13c 100644
--- a/goldberg.cpp
+++ b/goldberg.cpp
@@ -1441,11 +1441,17 @@ EX namespace gp {
       return C0;
       }
     };
-  
+
   EX hrmap* new_inverse() { return new hrmap_inverse; }
   
   hrmap_inverse* inv_map() { return (hrmap_inverse*)currentmap; }
 
+  EX bool inverse_pseudohept(cell *c) {
+    cell *c1 = inv_map()->mapping[c];
+    if(!c1) return false;
+    return UIU(pseudohept(c1));
+    }
+
   EX hrmap* get_underlying_map() { return inv_map()->underlying_map; }
   EX cell* get_mapped(cell *c) { return inv_map()->get_mapped(c, 0); }
   EX int untruncated_shift(cell *c) { return inv_map()->shift[c]; }
diff --git a/landgen.cpp b/landgen.cpp
index 5b377f3f..2bb047d8 100644
--- a/landgen.cpp
+++ b/landgen.cpp
@@ -1238,7 +1238,7 @@ EX void giantLandSwitch(cell *c, int d, cell *from) {
       if(fargen) {
         if(hrand(500) < 15) 
           createArrowTrapAt(c, laTerracotta);
-        if(pseudohept(c) && hrand(100) < 40 && c->wall == waNone && !racing::on) {
+        if(pseudohept_r(c) && hrand(100) < 40 && c->wall == waNone && !racing::on) {
           c->wall = waTerraWarrior;
           c->wparam = terracotta::randterra ? 0 : 3 + hrand(3);
           if(hrand(100) < items[itTerra]-10)
@@ -1521,7 +1521,7 @@ EX void giantLandSwitch(cell *c, int d, cell *from) {
       if(fargen) {
         if(randomPatternsMode)
           c->wall = RANDPAT ? ((RANDPATV(laCrossroads) || RANDPATV(laCrossroads2)) ? waAncientGrave : waFreshGrave) : waNone;
-        else if(pseudohept(c)) 
+        else if(pseudohept_r(c))
           c->wall = hrand(5) ? waAncientGrave : waFreshGrave;
         }
       ONEMPTY {
@@ -1554,7 +1554,7 @@ EX void giantLandSwitch(cell *c, int d, cell *from) {
                 c->move(i)->wall = waNone;
               }
             }
-          if(pseudohept(c) && hrand(2)) c->wall = waColumn;
+          if(pseudohept_r(c) && hrand(2)) c->wall = waColumn;
           }
         }
       ONEMPTY {
@@ -2273,7 +2273,7 @@ EX void giantLandSwitch(cell *c, int d, cell *from) {
           c->monst = moMonkey;
         else if(hrand_monster(80000) < 5 + items[itRuby] + yendor::hardness())
           c->monst = moEagle;
-        else if(pseudohept(c) && c != currentmap->gamestart() && hrand_monster(4000) < 300 + items[itRuby] && !c->monst) {
+        else if(pseudohept_r(c) && c != currentmap->gamestart() && hrand_monster(4000) < 300 + items[itRuby] && !c->monst) {
           int hardchance = items[itRuby] + yendor::hardness();
           if(hardchance > 25) hardchance = 25;
           bool hardivy = hrand(100) < hardchance;
diff --git a/pattern2.cpp b/pattern2.cpp
index 3acb1cf4..493feeb4 100644
--- a/pattern2.cpp
+++ b/pattern2.cpp
@@ -1493,7 +1493,7 @@ EX bool pseudohept(cell *c) {
   #endif
   if(arb::in()) return arb::pseudohept(c);
   #if CAP_GP
-  if(INVERSE) return false;
+  if(INVERSE) return gp::inverse_pseudohept(c);
   if(GOLDBERG && gp_threecolor() == 2)
     return gp::pseudohept_val(c) == 0;
   if(GOLDBERG && gp_threecolor() == 1 && (S7&1) && (S3 == 3))
@@ -1502,6 +1502,13 @@ EX bool pseudohept(cell *c) {
   return pattern_threecolor(c) == 0;
   }
 
+/** like pseudohept, but return randomly if no pseudohept is available */
+EX bool pseudohept_r(cell *c) {
+  if(UNTRUNCATED || UNRECTIFIED)
+    return hrand(100) < 20;
+  return pseudohept(c);
+  }
+
 // while Krakens movement is usually restricted to non-pseudohept cells,
 // there is one special case when this does not work (because non-pseudohept cells have varying degrees)
 EX bool kraken_pseudohept(cell *c) {