diff --git a/geometry.cpp b/geometry.cpp
index e47bf606..13182242 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -421,6 +421,8 @@ void geometry_information::prepare_basics() {
   
   hexshift = 0;
 
+  ld ALPHA = 2 * M_PI / S7;
+  
   ld fmin, fmax;  
 
   if(arcm::in() && !prod) 
diff --git a/hyper.h b/hyper.h
index a41e7f62..98faa8a8 100644
--- a/hyper.h
+++ b/hyper.h
@@ -109,7 +109,6 @@ void addMessage(string s, char spamtype = 0);
 
 #define cginf ginf[geometry]
 
-#define ALPHA (M_PI*2/S7)
 #define S7 cginf.sides
 #define S3 cginf.vertex
 #define hyperbolic_37 (S7 == 7 && S3 == 3 && !bt::in() && !arcm::in())
diff --git a/irregular.cpp b/irregular.cpp
index b04a550d..fcfe6532 100644
--- a/irregular.cpp
+++ b/irregular.cpp
@@ -520,7 +520,7 @@ bool step(int delta) {
         ld dist = cgi.hcrossf / 2;
         ld dists[8];
         for(int i=0; i<S7; i++) {
-          dists[i] = hdist(s.p, xspinpush0(cgi.hexshift - i * ALPHA, -cgi.hcrossf));
+          dists[i] = hdist(s.p, xspinpush0(cgi.hexshift - i * 2 * M_PI / S7, -cgi.hcrossf));
           if(dists[i] < dist)
             d = i, dist = dists[i];
           }
diff --git a/pattern2.cpp b/pattern2.cpp
index 5395229a..a19305f1 100644
--- a/pattern2.cpp
+++ b/pattern2.cpp
@@ -2628,7 +2628,7 @@ EX namespace linepatterns {
           if(pseudohept(c) && (p/4 == 10 || p/4 == 8))
           for(int i=0; i<S7; i++) if(c->move(i) && emeraldval(c->move(i)) == p-4) {
             gridlinef(V, C0, tC0(cgi.heptmove[i]), col, 2 + vid.linequality);
-            gridlinef(V, C0, xspinpush0(-i * ALPHA, -hdist/2), col, 2 + vid.linequality);
+            gridlinef(V, C0, xspinpush0(-i * 2 * M_PI / S7, -hdist/2), col, 2 + vid.linequality);
             }
           }
         break;