diff --git a/glass/_array_api_utils.py b/glass/_array_api_utils.py
index 5f8fa992..10284068 100644
--- a/glass/_array_api_utils.py
+++ b/glass/_array_api_utils.py
@@ -16,7 +16,11 @@ def get_namespace(*arrays: NDArray[Any] | Array) -> ModuleType:
     if they do not.
     """
     namespace = arrays[0].__array_namespace__()
-    if not all(array.__array_namespace__() == namespace for array in arrays):
+    if any(
+        array.__array_namespace__() != namespace
+        for array in arrays
+        if array is not None
+    ):
         msg = "input arrays should belong to the same array library"
         raise ValueError(msg)