diff --git a/backend/nn/llm/llama.py b/backend/nn/llm/llama.py
index 61294b00..abf4bd4f 100644
--- a/backend/nn/llm/llama.py
+++ b/backend/nn/llm/llama.py
@@ -1,4 +1,4 @@
-# https://github.com/comfyanonymous/ComfyUI/blob/v0.3.75/comfy/text_encoders/llama.py
+# https://github.com/Comfy-Org/ComfyUI/blob/master/comfy/text_encoders/llama.py
 
 import math
 from dataclasses import asdict, dataclass
@@ -133,13 +133,6 @@ class Gemma2_2B_Config:
     final_norm: bool = True
 
 
-def rotate_half(x):
-    """Rotates half the hidden dims of the input."""
-    x1 = x[..., : x.shape[-1] // 2]
-    x2 = x[..., x.shape[-1] // 2 :]
-    return torch.cat((-x2, x1), dim=-1)
-
-
 def precompute_freqs_cis(head_dim, position_ids, theta, rope_scale=None, rope_dims=None, device=None):
     if not isinstance(theta, list):
         theta = [theta]
@@ -168,7 +161,9 @@ def precompute_freqs_cis(head_dim, position_ids, theta, rope_scale=None, rope_di
         else:
             cos = cos.unsqueeze(1)
             sin = sin.unsqueeze(1)
-        out.append((cos, sin))
+
+        sin_split = sin.shape[-1] // 2
+        out.append((cos, sin[..., :sin_split], -sin[..., sin_split:]))
 
     if len(out) == 1:
         return out[0]
@@ -180,8 +175,18 @@ def apply_rope(xq, xk, freqs_cis):
     org_dtype = xq.dtype
     cos = freqs_cis[0]
     sin = freqs_cis[1]
-    q_embed = (xq * cos) + (rotate_half(xq) * sin)
-    k_embed = (xk * cos) + (rotate_half(xk) * sin)
+    nsin = freqs_cis[2]
+
+    q_embed = xq * cos
+    q_split = q_embed.shape[-1] // 2
+    q_embed[..., :q_split].addcmul_(xq[..., q_split:], nsin)
+    q_embed[..., q_split:].addcmul_(xq[..., :q_split], sin)
+
+    k_embed = xk * cos
+    k_split = k_embed.shape[-1] // 2
+    k_embed[..., :k_split].addcmul_(xk[..., k_split:], nsin)
+    k_embed[..., k_split:].addcmul_(xk[..., :k_split], sin)
+
     return q_embed.to(org_dtype), k_embed.to(org_dtype)