diff --git a/L1Trigger/L1TCommon/interface/ConvertToLUT.h b/L1Trigger/L1TCommon/interface/ConvertToLUT.h
index 39a7ff04524d3..822cf8e31622d 100644
--- a/L1Trigger/L1TCommon/interface/ConvertToLUT.h
+++ b/L1Trigger/L1TCommon/interface/ConvertToLUT.h
@@ -7,7 +7,7 @@
 
 namespace l1t {
 
-  l1t::LUT convertToLUT(const std::vector<uint64_t> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<uint64_t> &v, int padding = -1) noexcept {
     unsigned int addrWidth = (32 - __builtin_clz(uint32_t(v.size() - 1)));
     std::stringstream oss;
     oss << "#<header> V1 " << addrWidth << " 31 </header> " << std::endl;  // hardcode 32 bits for data
@@ -24,28 +24,28 @@ namespace l1t {
     return lut;
   }
 
-  l1t::LUT convertToLUT(const std::vector<char> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<char> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
-  l1t::LUT convertToLUT(const std::vector<short> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<short> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
-  l1t::LUT convertToLUT(const std::vector<int> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<int> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
-  l1t::LUT convertToLUT(const std::vector<long> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<long> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
-  l1t::LUT convertToLUT(const std::vector<long long> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<long long> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
-  l1t::LUT convertToLUT(const std::vector<unsigned char> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<unsigned char> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
-  l1t::LUT convertToLUT(const std::vector<unsigned short> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<unsigned short> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
-  l1t::LUT convertToLUT(const std::vector<unsigned int> &v, int padding = -1) noexcept {
+  inline l1t::LUT convertToLUT(const std::vector<unsigned int> &v, int padding = -1) noexcept {
     return convertToLUT(std::vector<uint64_t>(v.begin(), v.end()), padding);
   }
 }  // namespace l1t
diff --git a/L1Trigger/L1TNtuples/interface/MuonID.h b/L1Trigger/L1TNtuples/interface/MuonID.h
index 2eb85aba55816..0cdeafb802f04 100644
--- a/L1Trigger/L1TNtuples/interface/MuonID.h
+++ b/L1Trigger/L1TNtuples/interface/MuonID.h
@@ -16,7 +16,7 @@
 //local  data formats
 #include "L1Trigger/L1TNtuples/interface/L1AnalysisRecoVertexDataFormat.h"
 
-bool isLooseMuonCustom(const reco::Muon& recoMu) {
+inline bool isLooseMuonCustom(const reco::Muon& recoMu) {
   bool flag = false;
   if (recoMu.isPFMuon() && (recoMu.isGlobalMuon() || recoMu.isTrackerMuon()))
     flag = true;
@@ -24,7 +24,7 @@ bool isLooseMuonCustom(const reco::Muon& recoMu) {
   return flag;
 }
 
-bool isMediumMuonCustom(const reco::Muon& recoMu) {
+inline bool isMediumMuonCustom(const reco::Muon& recoMu) {
   bool goodGlob = recoMu.isGlobalMuon() && recoMu.globalTrack()->normalizedChi2() < 3 &&
                   recoMu.combinedQuality().chi2LocalPosition < 12 && recoMu.combinedQuality().trkKink < 20;
   bool isMedium = isLooseMuonCustom(recoMu) && recoMu.innerTrack()->validFraction() > 0.49 &&
@@ -33,7 +33,7 @@ bool isMediumMuonCustom(const reco::Muon& recoMu) {
   return isMedium;
 }
 
-bool isTightMuonCustom(const reco::Muon& recoMu, const reco::Vertex recoVtx) {
+inline bool isTightMuonCustom(const reco::Muon& recoMu, const reco::Vertex recoVtx) {
   //bp
   bool isTight = recoMu.isGlobalMuon() && recoMu.isPFMuon() && recoMu.globalTrack()->normalizedChi2() < 10. &&
                  recoMu.globalTrack()->hitPattern().numberOfValidMuonHits() > 0 &&