diff --git a/include/csg.hpp b/include/csg.hpp
index 23819fa3c1c3814ec0459f5bf7c3c9ea638c4cd2..6c41f0e8ead7faa11a6c3efcb34d4aa6730a8c30 100644
--- a/include/csg.hpp
+++ b/include/csg.hpp
@@ -1,12 +1,6 @@
 #ifndef CSG_H_
 #define CSG_H_
 
-#if defined(CSG_USE_GPU) && !defined(CSG_GPU_HOST_DEVICE)
-#define CSG_GPU_HOST_DEVICE __host__ __device__
-#else
-#define CSG_GPU_HOST_DEVICE
-#endif
-
 #include <array>
 #include <memory>
 #include <tuple>
@@ -14,17 +8,10 @@
 
 namespace csg {
 
-struct GPUable {};
-template <class D, class Enable = void> struct IsGPUable : std::false_type {};
-template <class D>
-struct IsGPUable<
-    D, typename std::enable_if<std::is_base_of<GPUable, D>::value>::type>
-    : std::true_type {};
-
 struct Tree;
 std::shared_ptr<Tree> parse_csg(std::string);
 
-class CsgIF : GPUable {
+class CsgIF {
 public:
   CsgIF(std::shared_ptr<Tree> a_state, bool is_internal_flow = false);
   CsgIF(const CsgIF &rhs);
@@ -33,7 +20,6 @@ public:
   CsgIF &operator=(CsgIF &&rhs) = delete;
   ~CsgIF();
 
-  CSG_GPU_HOST_DEVICE
   double operator()(double xx, double yy, double zz) const noexcept;
 
   inline double operator()(const std::array<double, 3> &p) const noexcept {