diff --git a/benchmark/polynomial_approximation/Makefile b/benchmark/polynomial_approximation/Makefile
index 482bf5f..5e090cb 100644
--- a/benchmark/polynomial_approximation/Makefile
+++ b/benchmark/polynomial_approximation/Makefile
@@ -42,4 +42,4 @@ parallel_workers: forward_parallel.cpp
 build: reverse forward forward_novec forward_gradlen
 
 clean:
-	rm primal_build_* forward_build_* reverse_build_* parallel_build_*
+	rm -f primal_build_* forward_build_* reverse_build_* parallel_build_*