diff --git a/rust/graphest-flint-sys/build.rs b/rust/graphest-flint-sys/build.rs
index 14c0039..b1b0f6a 100644
--- a/rust/graphest-flint-sys/build.rs
+++ b/rust/graphest-flint-sys/build.rs
@@ -50,6 +50,7 @@ fn load_cache(env: &Environment) {
 }
 
 fn build_flint(env: &Environment) {
+    let _ = copy_dir_all("@flint@", env.out_dir.clone());
     if env.lib_dir.join("libflint.a").exists() {
         return;
     }
diff --git a/rust/graphest-fftw-sys/build.rs b/rust/graphest-fftw-sys/build.rs
index 2e3247d..a4ac573 100644
--- a/rust/graphest-fftw-sys/build.rs
+++ b/rust/graphest-fftw-sys/build.rs
@@ -53,6 +53,8 @@ fn load_cache(env: &Environment) {
 }
 
 fn build(env: &Environment) {
+    let _ = copy_dir_all("@fftwLib@", env.out_dir.clone());
+    let _ = copy_dir_all("@fftwDev@", env.out_dir.clone());
     if env.lib_dir.join("libfftw3f.a").exists() {
         return;
     }
