diff --git a/cola/algorithms/arnoldi.py b/cola/algorithms/arnoldi.py
index 361df2e5..8db81b97 100644
--- a/cola/algorithms/arnoldi.py
+++ b/cola/algorithms/arnoldi.py
@@ -1,5 +1,6 @@
+from cola import Stiefel
 from cola.ops import LinearOperator
-from cola.ops import Array
+from cola.ops import Array, Dense
 from cola.ops import Householder, Product
 from cola.utils import export
 import cola
@@ -57,10 +58,8 @@ def arnoldi_eigs(A: LinearOperator, start_vector: Array = None, max_iters: int =
     Q, H, info = arnoldi(A=A, start_vector=start_vector, max_iters=max_iters, tol=tol, use_householder=use_householder,
                          pbar=pbar)
     xnp = A.xnp
-    eigvals, vs = xnp.eig(H)
-    eigvectors = Stiefel(lazify(xnp.cast(Q, dtype=vs.dtype))) @ lazify(vs)
-    # eigvectors = xnp.cast(eigvectors, dtype=A.dtype)
-    # eigvals = xnp.cast(eigvals, dtype=A.dtype)
+    eigvals, vs = xnp.eig(H.to_dense())
+    eigvectors = Q @ lazify(vs)
     return eigvals, eigvectors, info
 
 
@@ -86,7 +85,6 @@ def arnoldi(A: LinearOperator, start_vector=None, max_iters=100, tol: float = 1e
             - info (dict): General information about the iterative procedure.
     """
     xnp = A.xnp
-    xnp = A.xnp
     if start_vector is None:
         start_vector = xnp.randn(A.shape[-1], dtype=A.dtype, device=A.device)
     if len(start_vector.shape) == 1:
@@ -98,8 +96,11 @@ def arnoldi(A: LinearOperator, start_vector=None, max_iters=100, tol: float = 1e
     else:
         Q, H, _, infodict = get_arnoldi_matrix(A=A, rhs=rhs, max_iters=max_iters, tol=tol, pbar=pbar)
     if len(start_vector.shape) == 1:
-        return Q[0], H[0], infodict
-    return Q, H, infodict
+        return Stiefel(Dense(Q[0])), Dense(H[0]), infodict
+    else:
+        H = xnp.vmap(Dense)(H)
+        Q = Stiefel(xnp.vmap(Dense)(Q))
+        return Q, H, infodict
 
 
 def ArnoldiDecomposition(A: LinearOperator, start_vector=None, max_iters=100, tol=1e-7, use_householder=False,
diff --git a/cola/algorithms/gmres.py b/cola/algorithms/gmres.py
index 49a50c75..5f79a521 100644
--- a/cola/algorithms/gmres.py
+++ b/cola/algorithms/gmres.py
@@ -66,6 +66,7 @@ def gmres_fwd(A, rhs, x0, max_iters, tol, P, use_householder, use_triangular, pb
     res = rhs - A @ x0  # (m,k)
     Q, H, infodict = arnoldi(A=A, start_vector=res, max_iters=max_iters, tol=tol, pbar=pbar,
                              use_householder=use_householder)
+    Q, H = Q.to_dense(), H.to_dense()
 
     beta = xnp.norm(res, axis=-2)
     e1 = xnp.zeros(shape=(H.shape[1], beta.shape[0]), dtype=rhs.dtype, device=A.device)