diff --git a/backed-map.cpp b/backed-map.cpp
index 8d1a6b60..ec60302e 100644
--- a/backed-map.cpp
+++ b/backed-map.cpp
@@ -114,6 +114,23 @@ void backed_map::rebase(heptagon*& backer, transmatrix& T) {
     }
   }
 
+EX ld worst_precision_error;
+
+#if HDR
+struct hr_precision_error : hr_exception { hr_precision_error() : hr_exception("precision error") {} };
+#endif
+
+/** check if a and b are the same, testing for equality. Throw an exception or warning if not sure */
+EX bool same_point_may_warn(hyperpoint a, hyperpoint b) {
+  ld d = hdist(a, b);
+  if(d > 1e-2) return false;
+  if(d > 1e-3) throw hr_precision_error();
+  if(d > 1e-6 && worst_precision_error <= 1e-6)
+    addMessage("warning: precision errors are building up!");
+  if(d > worst_precision_error) worst_precision_error = d;
+  return true;
+  }
+
 bool in_hpe = false;
 
 void backed_map::handle_precision_errors(heptagon *h) {
diff --git a/hyperpoint.cpp b/hyperpoint.cpp
index ce2a6cbf..000ec4df 100644
--- a/hyperpoint.cpp
+++ b/hyperpoint.cpp
@@ -2037,23 +2037,6 @@ EX bool clockwise(hyperpoint h1, hyperpoint h2) {
   return h1[0] * h2[1] > h1[1] * h2[0];
   }
 
-EX ld worst_precision_error;
-
-#if HDR
-struct hr_precision_error : hr_exception { hr_precision_error() : hr_exception("precision error") {} };
-#endif
-
-/** check if a and b are the same, testing for equality. Throw an exception or warning if not sure */
-EX bool same_point_may_warn(hyperpoint a, hyperpoint b) {
-  ld d = hdist(a, b);
-  if(d > 1e-2) return false;
-  if(d > 1e-3) throw hr_precision_error();
-  if(d > 1e-6 && worst_precision_error <= 1e-6)
-    addMessage("warning: precision errors are building up!");
-  if(d > worst_precision_error) worst_precision_error = d;
-  return true;
-  }
-
 /** compute the area of a shape -- v.back() must equal v[0] */
 EX ld compute_area(const vector<hyperpoint>& v) {
   ld area = 0;