diff --git a/hysop/problem.py b/hysop/problem.py
index c5a33b6941af48a2a9cc270fe78067c5e12a501f..8f5b5b02607f9260a8c5b591f8b40fd5c97bd549 100644
--- a/hysop/problem.py
+++ b/hysop/problem.py
@@ -90,7 +90,7 @@ class Problem(ComputationalGraph):
                 vprint_banner(msg, at_border=2)
                 sys.exit(0)
         comm = self.mpi_params.comm
-        if self.domain.has_tasks:
+        if (not self.domain is None) and self.domain.has_tasks:
             comm = self.domain.parent_comm
         size = comm.Get_size()
         avg_time = comm.allreduce(tm.interval) / size
@@ -267,7 +267,7 @@ class Problem(ComputationalGraph):
                     self.profiler_report()
 
         comm = self.mpi_params.comm
-        if self.domain.has_tasks:
+        if (not self.domain is None) and self.domain.has_tasks:
             comm = self.domain.parent_comm
         size = comm.Get_size()
         avg_time = comm.allreduce(tm.interval) / size