diff --git a/jdaviz/core/marks.py b/jdaviz/core/marks.py
index fccb05e681..f01082c3a7 100644
--- a/jdaviz/core/marks.py
+++ b/jdaviz/core/marks.py
@@ -113,12 +113,14 @@ def set_y_unit(self, unit=None):
             if self.viewer.default_class is Spectrum1D:
                 spec = self.viewer.state.reference_data.get_object(cls=Spectrum1D)
                 eqv = u.spectral_density(spec.spectral_axis)
+
                 if ('_pixel_scale_factor' in spec.meta):
                     eqv += _eqv_pixar_sr(spec.meta['_pixel_scale_factor'])
-                    y = (self.y * self.yunit).to_value(unit, equivalencies=eqv)
-
-                # for flux <> flux/pix2
+                    
+                # add equiv for flux <> flux/pix2
                 eqv += _eqv_flux_to_sb_pixel()
+
+                y = (self.y * self.yunit).to_value(unit, equivalencies=eqv)
             else:
                 y = (self.y * self.yunit).to_value(unit)
             self.yunit = unit