diff --git a/build.rs b/build.rs
index b1a1371..1eeac71 100644
--- a/build.rs
+++ b/build.rs
@@ -29,6 +29,8 @@ fn main() {
         compile_cuda("cuda/pallas.cu", "pallas_msm_cuda", implement_sort);
         compile_cuda("cuda/vesta.cu", "vesta_msm_cuda", implement_sort);
         println!("cargo:rerun-if-changed=cuda");
+        println!("cargo:rerun-if-env-changed=CXXFLAGS");
+        println!("cargo:rustc-cfg=feature=\"cuda\"");
     }
     println!("cargo:rerun-if-env-changed=NVCC");
 }