diff --git a/src/rapids_singlecell/preprocessing/_scrublet/pipeline.py b/src/rapids_singlecell/preprocessing/_scrublet/pipeline.py
index 711b91ca..7f52ece0 100644
--- a/src/rapids_singlecell/preprocessing/_scrublet/pipeline.py
+++ b/src/rapids_singlecell/preprocessing/_scrublet/pipeline.py
@@ -78,9 +78,9 @@ def pca(
 
     self._counts_obs_norm = self._counts_obs_norm.astype(cp.float32)
     self._counts_sim_norm = self._counts_sim_norm.astype(cp.float32)
-    pca = PCA(n_components=n_prin_comps, random_state=random_state).fit(
-        self._counts_obs_norm
-    )
-    X_obs = pca.transform(self._counts_obs_norm)
-    X_sim = pca.transform(self._counts_sim_norm)
+    X_obs = _sparse_to_dense(self._counts_obs_norm)
+
+    pca = PCA(n_components=n_prin_comps, random_state=random_state).fit(X_obs)
+    X_obs = pca.transform(X_obs)
+    X_sim = pca.transform(_sparse_to_dense(self._counts_sim_norm))
     self.set_manifold(X_obs, X_sim)