diff --git a/ebos/eclmpiserializer.hh b/ebos/eclmpiserializer.hh
index f2cdbe075..02ed890d2 100644
--- a/ebos/eclmpiserializer.hh
+++ b/ebos/eclmpiserializer.hh
@@ -27,7 +27,7 @@ namespace Opm {
 
 class EclMpiSerializer {
 public:
-    EclMpiSerializer(Dune::CollectiveCommunication<Dune::MPIHelper::MPICommunicator> comm) :
+    explicit EclMpiSerializer(Dune::CollectiveCommunication<Dune::MPIHelper::MPICommunicator> comm) :
         m_comm(comm)
     {}