From c2f9f56c9859f99ccdc2ff128209473dd6b06923 Mon Sep 17 00:00:00 2001
From: Bernard Tan <30761156+thkkk@users.noreply.github.com>
Date: Thu, 9 Oct 2025 15:50:55 +0800
Subject: [PATCH] Added view(-1, 1) before expanding 1D tensors

expand()only works on dimensions of size 1
---
 wan/modules/model.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/wan/modules/model.py b/wan/modules/model.py
index 6982fa15..1c240ee6 100644
--- a/wan/modules/model.py
+++ b/wan/modules/model.py
@@ -458,6 +458,9 @@ def forward(
 
         # time embeddings
         if t.dim() == 1:
+            # Note: expand only works for dimensions of size 1; view(-1, 1) must be called first.
+            t = t.view(-1, 1).expand(t.size(0), seq_len)
+        elif t.dim() == 2 and t.size(1) == 1:
             t = t.expand(t.size(0), seq_len)
         with torch.amp.autocast('cuda', dtype=torch.float32):
             bt = t.size(0)