diff --git a/src/diffusers/schedulers/scheduling_unipc_multistep.py b/src/diffusers/schedulers/scheduling_unipc_multistep.py
index 5c2cbcc13ff1..e8f5af16fbe4 100644
--- a/src/diffusers/schedulers/scheduling_unipc_multistep.py
+++ b/src/diffusers/schedulers/scheduling_unipc_multistep.py
@@ -903,7 +903,7 @@ def multistep_uni_p_bh_update(
             rks.append(rk)
             D1s.append((mi - m0) / rk)
 
-        rks.append(torch.ones((), device=device))
+        rks.append(torch.ones_like(h))
         rks = torch.stack(rks)
 
         R = []
@@ -1038,7 +1038,7 @@ def multistep_uni_c_bh_update(
             rks.append(rk)
             D1s.append((mi - m0) / rk)
 
-        rks.append(torch.ones((), device=device))
+        rks.append(torch.ones_like(h))
         rks = torch.stack(rks)
 
         R = []
diff --git a/tests/schedulers/test_scheduler_unipc.py b/tests/schedulers/test_scheduler_unipc.py
index ac7e1d3f88b4..9f5c37667e58 100644
--- a/tests/schedulers/test_scheduler_unipc.py
+++ b/tests/schedulers/test_scheduler_unipc.py
@@ -257,6 +257,20 @@ def test_fp16_support(self):
 
                     assert sample.dtype == torch.float16
 
+    def test_default_dtype_float64(self):
+        default_dtype = torch.get_default_dtype()
+        torch.set_default_dtype(torch.float64)
+        try:
+            sample = self.full_loop(solver_order=3)
+        finally:
+            torch.set_default_dtype(default_dtype)
+
+        result_mean = torch.mean(torch.abs(sample))
+        reference_mean = torch.mean(torch.abs(self.full_loop(solver_order=3)))
+
+        assert sample.dtype == torch.float64
+        assert abs(result_mean.item() - reference_mean.item()) < 1e-3
+
     def test_full_loop_with_noise(self):
         scheduler_class = self.scheduler_classes[0]
         scheduler_config = self.get_scheduler_config()