diff --git a/src/model.py b/src/model.py
index 71bc098..1eeb086 100644
--- a/src/model.py
+++ b/src/model.py
@@ -69,7 +69,7 @@ class RWKV_TimeMix(nn.Module):
                 if h < config.n_head - 1:
                     decay_speed = math.pow(config.ctx_len, -(h+1)/(config.n_head-1))
                 else:
-                    decay_speed = 0
+                    decay_speed = 0.0
                 ww[h] = torch.exp(curve * decay_speed)
                 # print('layer', layer_id, 'head', h, 'decay_speed', round(decay_speed, 4), ww[h][:5].numpy(), '...', ww[h][-5:].numpy())
         self.time_w = nn.Parameter(ww)