diff --git a/gui/src/aaregui/threads/daq_worker.py b/gui/src/aaregui/threads/daq_worker.py
index 6d3ac630..c88937ae 100644
--- a/gui/src/aaregui/threads/daq_worker.py
+++ b/gui/src/aaregui/threads/daq_worker.py
@@ -26,6 +26,7 @@ class DAQWorker(QObject):
     reference_tools = Signal(SampleShortInfoList)
     http_error = Signal(str)
     auth_error = Signal()
+    sample_missing = Signal(str)
     automated_scan_done = Signal(int, bool)  # sample ID, success
     run_number_incremented = Signal()
     raster_scan_completed = Signal(CompletedRasterGrid)