diff --git a/ldm/modules/attention.py b/ldm/modules/attention.py
index d504d93..574951c 100644
--- a/ldm/modules/attention.py
+++ b/ldm/modules/attention.py
@@ -201,7 +201,7 @@ class MemoryEfficientCrossAttention(nn.Module):
         self.to_v = nn.Linear(context_dim, inner_dim, bias=False)
 
         self.to_out = nn.Sequential(nn.Linear(inner_dim, query_dim), nn.Dropout(dropout))
-        self.attention_op: Optional[Any] = None
+        self.attention_op: Optional[Any] = xformers.ops.MemoryEfficientAttentionCutlassOp if hasattr(xformers.ops, "MemoryEfficientAttentionCutlassOp") else None
 
     def forward(self, x, context=None, mask=None):
         q = self.to_q(x)
diff --git a/ldm/modules/diffusionmodules/model.py b/ldm/modules/diffusionmodules/model.py
index b089eeb..af5bdb3 100644
--- a/ldm/modules/diffusionmodules/model.py
+++ b/ldm/modules/diffusionmodules/model.py
@@ -234,7 +234,7 @@ class MemoryEfficientAttnBlock(nn.Module):
                                         kernel_size=1,
                                         stride=1,
                                         padding=0)
-        self.attention_op: Optional[Any] = None
+        self.attention_op: Optional[Any] = xformers.ops.MemoryEfficientAttentionCutlassOp if hasattr(xformers.ops, "MemoryEfficientAttentionCutlassOp") else None
 
     def forward(self, x):
         h_ = x