diff --git a/src/cellrank/estimators/_base_estimator.py b/src/cellrank/estimators/_base_estimator.py
index b535fddf4..8ac5952e2 100644
--- a/src/cellrank/estimators/_base_estimator.py
+++ b/src/cellrank/estimators/_base_estimator.py
@@ -58,7 +58,7 @@ def __init__(
 
         self._params: dict[str, Any] = {}
         self._shadow_adata = AnnData(
-            X=sp.csr_matrix(self.adata.shape, dtype=self.adata.X.dtype),
+            X=None if self.adata.X is None else sp.csr_matrix(self.adata.shape, dtype=self.adata.X.dtype),
             obs=self.adata.obs[[]].copy(),
             var=self.adata.var[[]].copy(),
             raw=None if self.adata.raw is None else self.adata.raw.to_adata(),
diff --git a/tests/test_gpcca.py b/tests/test_gpcca.py
index 09c0d3e9e..c02c93071 100644
--- a/tests/test_gpcca.py
+++ b/tests/test_gpcca.py
@@ -1074,6 +1074,13 @@ def test_to_adata(self, adata_large: AnnData, state: State):
         _assert_adata(adata, state, fwd=False)
         _assert_adata(adata, state, fwd=True)
 
+    def test_adata_without_x(self, adata_large: AnnData):
+        adata_large.X = None
+        g = _fit_gpcca(adata_large, State.FATE_PROBS)
+        adata = g.to_adata()
+        assert adata.X is None
+        _assert_adata(adata, State.FATE_PROBS, fwd=False)
+
     @pytest.mark.parametrize("copy", [False, True])
     @pytest.mark.parametrize("keep", ["X", ("obs", "obsm"), ("layers",)])
     def test_to_adata_keep(self, adata_large: AnnData, keep: str | Sequence[str], copy: bool):