diff --git a/sources/evolution.F90 b/sources/evolution.F90
index 8db757e..423906f 100644
--- a/sources/evolution.F90
+++ b/sources/evolution.F90
@@ -4446,7 +4446,7 @@ module evolution
     use equations  , only : nf, errors
     use helpers    , only : print_message
 #ifdef MPI
-    use mpitools   , only : reduce_sum
+    use mpitools   , only : reduce_maximum
 #endif /* MPI */
     use workspace  , only : resize_workspace, work, work_in_use