Index: lnt/server/ui/views.py
===================================================================
--- lnt/server/ui/views.py
+++ lnt/server/ui/views.py
@@ -397,12 +397,13 @@
         baseline_str = request.args.get('baseline')
         if baseline_str:
             baseline_id = int(baseline_str)
-            baseline = session.query(ts.Run).filter_by(id=baseline_id).first()
-            if baseline is None:
-                flash("Could not find baseline " + baseline_str, FLASH_DANGER)
         else:
-            baseline = None
+            baseline_id = flask.session.get(baseline_key())
 
+        baseline = session.query(ts.Run).filter_by(id=baseline_id).first()
+        if baseline is None and baseline_str:
+            flash("Could not find baseline " + baseline_str, FLASH_DANGER)
+
         # Gather the runs to use for statistical data.
         comparison_start_run = compare_to or self.run