diff --git a/examples/cuda_matmul_opt.py b/examples/cuda_matmul_opt.py
index 1297a8ad..62865e85 100644
--- a/examples/cuda_matmul_opt.py
+++ b/examples/cuda_matmul_opt.py
@@ -293,7 +293,7 @@ def matmul_mod():
     if "shared" in kernel_name:
         shared_mem = 2 * BLOCK_SIZE * BLOCK_SIZE * npy_dtype().nbytes
     else:
-        shared_mem = None
+        shared_mem = 0
 
     cuda_func(
         grid_dims,
diff --git a/requirements.txt b/requirements.txt
index 30a79294..be88e418 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,4 +5,4 @@ bytecode
 inflection
 numpy
 astunparse
-cloudpickle
\ No newline at end of file
+cloudpickle>=3.0.0
\ No newline at end of file