diff --git a/mantidimaging/gui/windows/spectrum_viewer/model.py b/mantidimaging/gui/windows/spectrum_viewer/model.py
index 912b92b1e8e..583b220c1b2 100644
--- a/mantidimaging/gui/windows/spectrum_viewer/model.py
+++ b/mantidimaging/gui/windows/spectrum_viewer/model.py
@@ -208,7 +208,7 @@ def save_rits(self, path: Path, normalized: bool) -> None:
         # RITS expects ToF in μs
         tof *= 1e6
 
-        transmission_error = np.zeros_like(tof)
+        transmission_error = np.full_like(tof, 0.1)
         if normalized:
             if self._normalise_stack is None:
                 raise RuntimeError("No normalisation stack selected")