diff --git a/bezier.cpp b/bezier.cpp
index 678b12d9..5e85f344 100644
--- a/bezier.cpp
+++ b/bezier.cpp
@@ -144,7 +144,7 @@ namespace util {
     std::array<util::vector2f,4>
     bezier<3>::coeffs (void) const
     {
-        auto &v = reinterpret_cast<const util::vector2f(&)[4]> (m_points);
+        const auto &v = m_coeffs;
 
         return {
             -1 * v[0] +3 * v[1] -3 * v[2] +1 * v[3],
@@ -162,7 +162,7 @@ namespace util {
     std::array<util::vector2f,3>
     bezier<2>::coeffs (void) const
     {
-        auto &v = reinterpret_cast<const util::vector2f(&)[3]> (m_points);
+        auto &v = m_coeffs;
 
         return {
             +1 * v[2] -2 * v[1] + 1 * v[0],
@@ -179,7 +179,7 @@ namespace util {
     std::array<util::vector2f,2>
     bezier<1>::coeffs (void) const
     {
-        auto &v = reinterpret_cast<const util::vector2f(&)[2]> (m_points);
+        auto &v = m_coeffs;
 
         return {
             -1 * v[1] + 1 * v[0],
diff --git a/bezier.hpp b/bezier.hpp
index d6919a07..287a9212 100644
--- a/bezier.hpp
+++ b/bezier.hpp
@@ -44,7 +44,12 @@ namespace util {
         const point2f& operator[] (size_t idx) const;
 
     private:
-        point2f m_points[S+1];
+        // HACK: allow easy access to component-wise arithmetic using
+        // vector2f rather than point2f in the implementation.
+        union {
+            point2f  m_points[S+1];
+            vector2f m_coeffs[S+1];
+        };
     };
 
     template <size_t S>