diff --git a/comfy/model_management.py b/comfy/model_management.py
index 145a32080..c1d0901fc 100644
--- a/comfy/model_management.py
+++ b/comfy/model_management.py
@@ -1196,7 +1196,10 @@ def get_pin_buffer(offload_stream):
         pin_buffer = comfy_aimdo.host_buffer.HostBuffer(0)
         STREAM_PIN_BUFFERS[offload_stream] = pin_buffer
     elif offload_stream is not None:
-        offload_stream.synchronize()
+        event = getattr(pin_buffer, "_comfy_event", None)
+        if event is not None:
+            event.synchronize()
+            delattr(pin_buffer, "_comfy_event")
     return pin_buffer
 
 def resize_pin_buffer(pin_buffer, size):
diff --git a/comfy/ops.py b/comfy/ops.py
index d425ea7eb..be744a030 100644
--- a/comfy/ops.py
+++ b/comfy/ops.py
@@ -241,6 +241,7 @@ def cast_modules_with_vbar(comfy_modules, dtype, device, bias_dtype, non_blockin
             pin = stream_pin_tensor[pin_offset:pin_offset + pin_size]
             cast_maybe_lowvram_patch(xfer_source, pin, None)
             comfy.model_management.cast_to_gathered([ pin ], xfer_dest, non_blocking=non_blocking, stream=offload_stream)
+        stream_pin_hostbuf._comfy_event = offload_stream.record_event()
 
     return offload_stream