diff --git a/pylot/core/pick/compare.py b/pylot/core/pick/compare.py
index ed769fc9..63a20192 100644
--- a/pylot/core/pick/compare.py
+++ b/pylot/core/pick/compare.py
@@ -270,6 +270,8 @@ class PDFDictionary(object):
 
         for station, phases in pdf_picks.items():
             for phase, values in phases.items():
+                if phase not in 'PS':
+                    continue
                 phases[phase] = ProbabilityDensityFunction.from_pick(
                     values['epp'],
                     values['mpp'],