diff --git a/converter/include/k4SimDelphes/DelphesEDM4HepConverter.h b/converter/include/k4SimDelphes/DelphesEDM4HepConverter.h
index 6cd9826..ccfd800 100644
--- a/converter/include/k4SimDelphes/DelphesEDM4HepConverter.h
+++ b/converter/include/k4SimDelphes/DelphesEDM4HepConverter.h
@@ -68,7 +68,7 @@ namespace k4SimDelphes {
     std::string className;
   };
 
-  std::vector<BranchSettings> getBranchSettings(ExRootConfParam /*const&*/ treeConf) {
+  inline std::vector<BranchSettings> getBranchSettings(ExRootConfParam /*const&*/ treeConf) {
     std::vector<k4SimDelphes::BranchSettings> branches;
     for (int b = 0; b < treeConf.GetSize(); b += 3) {
       k4SimDelphes::BranchSettings branch{treeConf[b].GetString(), treeConf[b + 1].GetString(),
diff --git a/converter/include/k4SimDelphes/DelphesEDM4HepOutputConfiguration.h b/converter/include/k4SimDelphes/DelphesEDM4HepOutputConfiguration.h
index 36945ce..02b366e 100644
--- a/converter/include/k4SimDelphes/DelphesEDM4HepOutputConfiguration.h
+++ b/converter/include/k4SimDelphes/DelphesEDM4HepOutputConfiguration.h
@@ -161,7 +161,7 @@ namespace k4SimDelphes {
     return settings;
   }
 
-  OutputSettings getEDM4hepOutputSettings(const char* confFile) {
+  inline OutputSettings getEDM4hepOutputSettings(const char* confFile) {
     ExRootConfReader confReader{};
     confReader.ReadFile(confFile);
     return getEDM4hepOutputSettings(&confReader);