diff --git a/httomo/base_block.py b/httomo/base_block.py
index 9334f6991..e1bb0c61a 100644
--- a/httomo/base_block.py
+++ b/httomo/base_block.py
@@ -111,7 +111,7 @@ def to_gpu(self):
         self._data = xp.asarray(self.data, order="C")
 
     def to_cpu(self):
-        if not gpu_enabled:
+        if not gpu_enabled or xp.get_array_module(self.data).__name__ == "numpy":
             return
         self._data = xp.asnumpy(self.data, order="C")
 
diff --git a/httomo/method_wrappers/generic.py b/httomo/method_wrappers/generic.py
index a41180ff4..92ede0250 100644
--- a/httomo/method_wrappers/generic.py
+++ b/httomo/method_wrappers/generic.py
@@ -319,7 +319,10 @@ def execute(self, block: T) -> T:
             block = self._run_method(block, args)
             block = self._postprocess_data(block)
 
-        self._gpu_time_info.kernel = t.elapsed
+        if xp.get_array_module(block.data).__name__ == "cupy":
+            self._gpu_time_info.kernel = t.elapsed
+        else:
+            self._gpu_time_info.kernel = 0
 
         return block