diff --git a/skyllh/analyses/i3/publicdata_ps/pdfratio.py b/skyllh/analyses/i3/publicdata_ps/pdfratio.py
index 7abdbb3dac..7089cb918b 100644
--- a/skyllh/analyses/i3/publicdata_ps/pdfratio.py
+++ b/skyllh/analyses/i3/publicdata_ps/pdfratio.py
@@ -213,7 +213,7 @@ def _get_ratio_values(
         (bkg_pd,) = tdm.broadcast_selected_events_arrays_to_values_arrays(
             (bkg_pd,))
 
-        m_nonzero_bkg = bkg_pd > 0
+        m_nonzero_bkg = bkg_pd > np.finfo(np.double).resolution
         m_zero_bkg = np.invert(m_nonzero_bkg)
         if np.any(m_zero_bkg):
             ev_idxs = np.where(m_zero_bkg)[0]