diff --git a/core/src/Cabana_CommunicationPlan.hpp b/core/src/Cabana_CommunicationPlan.hpp
index d0423fb5f..2d02092a9 100644
--- a/core/src/Cabana_CommunicationPlan.hpp
+++ b/core/src/Cabana_CommunicationPlan.hpp
@@ -356,7 +356,7 @@ auto countSendsAndCreateSteering( const ExportRankView element_export_ranks,
 
 //---------------------------------------------------------------------------//
 // Return unique neighbor ranks, with the current rank first.
-std::vector<int> getUniqueTopology( std::vector<int> topology )
+inline std::vector<int> getUniqueTopology( std::vector<int> topology )
 {
     auto remove_end = std::remove( topology.begin(), topology.end(), -1 );
     std::sort( topology.begin(), remove_end );