diff --git a/src/pyro/core/utils.py b/src/pyro/core/utils.py
index 02c8e9b..9526963 100644
--- a/src/pyro/core/utils.py
+++ b/src/pyro/core/utils.py
@@ -295,6 +295,10 @@ def get(self, name: str, suffix: str | None = None) -> typing.Any:
                 raise KeyError(
                     f"No object called '{name}' found in the '{self._name}' registrar"
                 )
+        elif ret is None:
+            raise KeyError(
+                f"No object called '{name}' found in the '{self._name}' registrar"
+            )
         return ret
 
     def __contains__(self, name: str) -> bool:
diff --git a/src/pyro/model/networks.py b/src/pyro/model/networks.py
index 02fefb4..770d186 100644
--- a/src/pyro/model/networks.py
+++ b/src/pyro/model/networks.py
@@ -88,7 +88,7 @@ def _update(self, net: nn.Module, update_fn: typing.Callable) -> None:
             net.state_dict().values(),
             strict=True,
         ):
-            if self.device:
+            if self._device:
                 net_v = net_v.to(device=self.device)
             ema_v.copy_(update_fn(ema_v, net_v))