diff --git a/scar/main/_setup.py b/scar/main/_setup.py
index 7fe6d25..1d9778b 100644
--- a/scar/main/_setup.py
+++ b/scar/main/_setup.py
@@ -142,7 +142,7 @@ def setup_anndata(
         )
         for b in range(n_batch):
             try:
-                count_batch = raw_adata[batch_idx == b].X.astype(int).A
+                count_batch = raw_adata[batch_idx == b].X.astype(int).toarray()
             except MemoryError:
                 raise MemoryError("use more batches by setting a higher n_batch")
             log_prob_batch = Multinomial(