diff --git a/CUDAStream.cu b/CUDAStream.cu
index 043c8c7..7b1e0df 100644
--- a/CUDAStream.cu
+++ b/CUDAStream.cu
@@ -77,6 +77,8 @@ CUDAStream<T>::~CUDAStream()
   check_error();
   cudaFree(d_c);
   check_error();
+  cudaFree(d_sum);
+  check_error();
 }