diff --git a/timm/utils/model_ema.py b/timm/utils/model_ema.py
index 073d5c5e..6c481449 100644
--- a/timm/utils/model_ema.py
+++ b/timm/utils/model_ema.py
@@ -117,10 +117,11 @@ class ModelEmaV2(nn.Module):
             for ema_v, model_v in zip(self.module.state_dict().values(), model.state_dict().values()):
                 if self.device is not None:
                     model_v = model_v.to(device=self.device)
-                ema_v.copy_(update_fn(ema_v, model_v))
+                if model_v.is_floating_point():
+                    update_fn(ema_v, model_v)
 
     def update(self, model):
-        self._update(model, update_fn=lambda e, m: self.decay * e + (1. - self.decay) * m)
+        self._update(model, update_fn=lambda e, m: e.mul_(self.decay).add_(m, alpha=1 - self.decay))
 
     def set(self, model):
         self._update(model, update_fn=lambda e, m: m)