diff --git a/src/dexorder/base/orderlib.py b/src/dexorder/base/orderlib.py
index e02958e..41ae63f 100644
--- a/src/dexorder/base/orderlib.py
+++ b/src/dexorder/base/orderlib.py
@@ -17,6 +17,7 @@ class SwapOrderState (Enum):
     Canceled = 3
     Expired = 4
     Filled = 5
+    Error = 99
 
     @property
     def is_open(self):
diff --git a/src/dexorder/event_handler.py b/src/dexorder/event_handler.py
index 87d9de6..635b7d3 100644
--- a/src/dexorder/event_handler.py
+++ b/src/dexorder/event_handler.py
@@ -273,6 +273,10 @@ def finish_execution_request(req: TrancheExecutionRequest, error: str):
     except KeyError:
         pass
     if error != '':
+        if error == 'NO':
+            # order is not open
+            log.error(f'Order {OrderKey(tk.vault,tk.order_index)} was closed, undetected!')
+            order.complete(SwapOrderState.Expired)
         log.debug(f'execution request for tranche {tk} had error "{error}"')
     if error == '':
         log.debug(f'execution request for tranche {tk} was successful!')