diff --git a/geom/cylinder.cpp b/geom/cylinder.cpp
index 36091041..b4c3cf5f 100644
--- a/geom/cylinder.cpp
+++ b/geom/cylinder.cpp
@@ -22,16 +22,16 @@ using util::geom::cylinder;
 ///////////////////////////////////////////////////////////////////////////////
 template <size_t S, typename T>
 bool
-cylinder<S,T>::includes (util::point<S,T> p) const
+cylinder<S,T>::includes (util::point<S,T> p_) const
 {
-    auto ab = b - a;
-    auto pa = p - a;
+    auto p10 = p1 - p0;
+    auto p_0 = p_ - p0;
 
-    auto l = dot (ab, pa);
-    if (l < 0 || l > ab.magnitude2 ())
+    auto l = dot (p10, p_0);
+    if (l < 0 || l > p10.magnitude2 ())
         return false;
 
-    auto d = dot (pa, pa) - l * l * ab.magnitude2 ();
+    auto d = dot (p10, p10) - l * l * p10.magnitude2 ();
     if (d > radius * radius)
         return false;
 
diff --git a/geom/cylinder.hpp b/geom/cylinder.hpp
index d3d71b03..778d5394 100644
--- a/geom/cylinder.hpp
+++ b/geom/cylinder.hpp
@@ -23,7 +23,7 @@ namespace util { namespace geom {
     ///////////////////////////////////////////////////////////////////////////
     template <size_t S, typename T>
     struct cylinder {
-        util::point<S,T> a, b;
+        util::point<S,T> p0, p1;
         T radius;
 
         float distance (util::point<S,T>) const;