diff --git a/src/epicell.m b/src/epicell.m
index 72ec6d98f015e47b4d432a3b9abd204bd7b8267d..3f2d48f6a23ff49146bddbb21c9777136e7d94e7 100644
--- a/src/epicell.m
+++ b/src/epicell.m
@@ -138,6 +138,8 @@ classdef epicell
         end
         
         function E = fit_plane( p )
+            c = mean( p );
+            p = p - repmat( c, size( p, 1 ), 1 );
             % Fit a plane to these points.
             [ ~, ~, v ] = svd( p );
             E = rot2eulerZXZ( v );