diff --git a/mantidimaging/gui/windows/spectrum_viewer/model.py b/mantidimaging/gui/windows/spectrum_viewer/model.py
index dda8097fb50..9044fbb70ea 100644
--- a/mantidimaging/gui/windows/spectrum_viewer/model.py
+++ b/mantidimaging/gui/windows/spectrum_viewer/model.py
@@ -567,3 +567,8 @@ def set_tof_unit_mode_for_stack(self) -> None:
         else:
             self.tof_mode = ToFUnitMode.WAVELENGTH
             self.presenter.change_selected_menu_option("Wavelength")
+
+    def get_roi(self, roi_name: str) -> SensibleROI:
+        if roi_name not in self._roi_ranges.keys():
+            raise KeyError(f"ROI {roi_name} does not exist in roi_ranges {self._roi_ranges.keys()}")
+        return self._roi_ranges[roi_name]
diff --git a/mantidimaging/gui/windows/spectrum_viewer/presenter.py b/mantidimaging/gui/windows/spectrum_viewer/presenter.py
index 4f99be83ef1..9a7d4b4293d 100644
--- a/mantidimaging/gui/windows/spectrum_viewer/presenter.py
+++ b/mantidimaging/gui/windows/spectrum_viewer/presenter.py
@@ -331,9 +331,7 @@ def do_add_roi(self) -> None:
         if roi_name in self.view.spectrum_widget.roi_dict:
             raise ValueError(f"ROI name already exists: {roi_name}")
         self.model.set_new_roi(roi_name)
-        roi = self.model._roi_ranges.get(roi_name)
-        if roi is None:
-            raise ValueError(f"ROI for {roi_name} is not valid.")
+        roi = self.model.get_roi(roi_name)
         self.view.spectrum_widget.add_roi(roi, roi_name)
         spectrum = self.model.get_spectrum(roi, self.spectrum_mode, self.view.shuttercount_norm_enabled())
         self.view.set_spectrum(roi_name, spectrum)