diff --git a/jdaviz/configs/cubeviz/plugins/slice/tests/test_slice.py b/jdaviz/configs/cubeviz/plugins/slice/tests/test_slice.py
index febfc47cf2..a2174f9d69 100644
--- a/jdaviz/configs/cubeviz/plugins/slice/tests/test_slice.py
+++ b/jdaviz/configs/cubeviz/plugins/slice/tests/test_slice.py
@@ -45,7 +45,7 @@ def test_slice(cubeviz_helper, spectrum1d_cube):
     # from the widget this logic is duplicated (to avoid sending logic through messages)
     sl._on_value_updated({'new': '4.62e-07'})
     assert sl.slice == 0
-    assert np.allclose(sl.wavelength, 4.62280007e-07)
+    assert np.allclose(sl.value, 4.62280007e-07)
 
     # make sure that passing an invalid value from the UI would revert to the previous value
     # JS strips invalid characters, but doesn't ensure its float-compatible
diff --git a/jdaviz/configs/cubeviz/plugins/spectral_extraction/spectral_extraction.py b/jdaviz/configs/cubeviz/plugins/spectral_extraction/spectral_extraction.py
index b8736d1d9a..a1872e4472 100644
--- a/jdaviz/configs/cubeviz/plugins/spectral_extraction/spectral_extraction.py
+++ b/jdaviz/configs/cubeviz/plugins/spectral_extraction/spectral_extraction.py
@@ -162,7 +162,7 @@ def slice_plugin(self):
     @observe('wavelength_dependent', 'bg_wavelength_dependent')
     def _wavelength_dependent_changed(self, *args):
         if self.wavelength_dependent:
-            self.reference_wavelength = self.slice_plugin.wavelength
+            self.reference_wavelength = self.slice_plugin.value
         else:
             self.bg_wavelength_dependent = False
         # NOTE: this can be redundant in the case where reference_wavelength changed and triggers