diff --git a/micro_sam/models/peft_sam.py b/micro_sam/models/peft_sam.py
index febbccf6..7677f2e5 100644
--- a/micro_sam/models/peft_sam.py
+++ b/micro_sam/models/peft_sam.py
@@ -23,10 +23,11 @@ class LoRASurgery(nn.Module):
         rank: The rank of the decomposition matrices for updating weights in each attention layer.
         block: The chosen attention blocks for implementing lora.
     """
-    def __init__(self, rank: int, block: nn.Module):
+    def __init__(self, rank: int, block: nn.Module, alpha: float):
         super().__init__()
         self.qkv_proj = block.attn.qkv
         self.dim = self.qkv_proj.in_features
+        self.alpha = alpha
 
         self.w_a_linear_q = nn.Linear(self.dim, rank, bias=False)
         self.w_b_linear_q = nn.Linear(rank, self.dim, bias=False)
@@ -45,8 +46,8 @@ def reset_parameters(self):
 
     def forward(self, x):
         qkv = self.qkv_proj(x)  # B, N, N, 3 * org_C
-        new_q = self.w_b_linear_q(self.w_a_linear_q(x))
-        new_v = self.w_b_linear_v(self.w_a_linear_v(x))
+        new_q = self.alpha / self.rank * self.w_b_linear_q(self.w_a_linear_q(x))
+        new_v = self.alpha / self.rank * self.w_b_linear_v(self.w_a_linear_v(x))
         qkv[:, :, :, :self.dim] += new_q
         qkv[:, :, :, -self.dim:] += new_v
         return qkv