diff --git a/geometry2.cpp b/geometry2.cpp
index 42f599c5..d97d3541 100644
--- a/geometry2.cpp
+++ b/geometry2.cpp
@@ -250,7 +250,7 @@ horo_distance::horo_distance(shiftpoint h1, const shiftmatrix& T) {
 #endif
   if(sn::in() || mhybrid || nil) become(inverse_shift(T, h1));
   else
-    a = 0, b = intval(h1.h, unshift(tC0(T), h1.shift));
+    a = 0, b = intval(h1.h, unshift(T * tile_center(), h1.shift));
   }
 
 bool horo_distance::operator < (const horo_distance z) const {
diff --git a/shmup.cpp b/shmup.cpp
index e0959843..c6b67087 100644
--- a/shmup.cpp
+++ b/shmup.cpp
@@ -154,7 +154,7 @@ cell *findbaseAround(shiftpoint p, cell *around, int maxsteps) {
   }
 
 cell *findbaseAround(const shiftmatrix& H, cell *around, int maxsteps) {
-  return findbaseAround(tC0(H), around, maxsteps);
+  return findbaseAround(H * tile_center(), around, maxsteps);
   }
 
 /* double distance(hyperpoint h) {