diff --git a/examples/algorithms/moo/nsga2/nsga2_pcx.py b/examples/algorithms/moo/nsga2/nsga2_pcx.py
index 10d0dd258..b5fa37f14 100644
--- a/examples/algorithms/moo/nsga2/nsga2_pcx.py
+++ b/examples/algorithms/moo/nsga2/nsga2_pcx.py
@@ -14,7 +14,7 @@
                algorithm,
                ('n_gen', 200),
                seed=1,
-               verbose=False)
+               verbose=True)
 
 plot = Scatter()
 plot.add(problem.pareto_front(), plot_type="line", color="black", alpha=0.7)
diff --git a/pymoo/util/display/single.py b/pymoo/util/display/single.py
index 06bb31d17..e178af672 100644
--- a/pymoo/util/display/single.py
+++ b/pymoo/util/display/single.py
@@ -60,9 +60,8 @@ def update(self, algorithm):
 
         if opt.feas:
             self.f_min.set(opt.f)
-            if self.best:
+            if self.best is not None:
                 self.f_gap.set(opt.f - self.best)
-
         else:
             self.f_min.set(None)
             self.f_gap.set(None)