diff --git a/L1Trigger/Phase2L1ParticleFlow/interface/egamma/pftkegalgo_ref.h b/L1Trigger/Phase2L1ParticleFlow/interface/egamma/pftkegalgo_ref.h
index 7b2377f6a50e..2f92d7129202 100644
--- a/L1Trigger/Phase2L1ParticleFlow/interface/egamma/pftkegalgo_ref.h
+++ b/L1Trigger/Phase2L1ParticleFlow/interface/egamma/pftkegalgo_ref.h
@@ -233,7 +233,7 @@ namespace l1ct {
     static std::unique_ptr<WP> createWP(const std::vector<double> &bin_low_edges,
                                         const std::vector<double> &wp_values) {
       assert(bin_low_edges.size() == wp_values.size() && "The size of bin_low_edges must match the size of wp_values.");
-      assert(wp_values.size() && "The size of bin_low_edges must not be 0.");
+      assert(!wp_values.empty() && "The size of bin_low_edges must not be 0.");
 
       std::vector<id_score_t> wp_values_apf;
       wp_values_apf.reserve(wp_values.size());
diff --git a/L1Trigger/Phase2L1ParticleFlow/interface/regionizer/tdr_regionizer_elements_ref.icc b/L1Trigger/Phase2L1ParticleFlow/interface/regionizer/tdr_regionizer_elements_ref.icc
index 2a5d54c9211f..0b878d95e680 100644
--- a/L1Trigger/Phase2L1ParticleFlow/interface/regionizer/tdr_regionizer_elements_ref.icc
+++ b/L1Trigger/Phase2L1ParticleFlow/interface/regionizer/tdr_regionizer_elements_ref.icc
@@ -342,12 +342,12 @@ bool l1ct::tdr_regionizer::Regionizer<T>::isInBigRegionLoose(const PFRegionEmu&
 }
 
 template <>
-bool l1ct::tdr_regionizer::Regionizer<l1ct::HadCaloObjEmu>::isInBigRegionLoose(const PFRegionEmu& reg) const {
+inline bool l1ct::tdr_regionizer::Regionizer<l1ct::HadCaloObjEmu>::isInBigRegionLoose(const PFRegionEmu& reg) const {
   return isInBigRegion(reg);
 }
 
 template <>
-bool l1ct::tdr_regionizer::Regionizer<l1ct::EmCaloObjEmu>::isInBigRegionLoose(const PFRegionEmu& reg) const {
+inline bool l1ct::tdr_regionizer::Regionizer<l1ct::EmCaloObjEmu>::isInBigRegionLoose(const PFRegionEmu& reg) const {
   return isInBigRegion(reg);
 }
 
@@ -556,7 +556,7 @@ bool l1ct::tdr_regionizer::Regionizer<T>::isDuplicate(int locphi, size_t logicBu
 
 // specialize for GCT  (CHECK ESPECIALLY EDGES)
 template <>
-bool l1ct::tdr_regionizer::Regionizer<l1ct::HadCaloObjEmu>::isDuplicate(int locphi, size_t logicBufIdx) const {
+inline bool l1ct::tdr_regionizer::Regionizer<l1ct::HadCaloObjEmu>::isDuplicate(int locphi, size_t logicBufIdx) const {
   auto odd = logicBufIdx % 2;
   if (odd) {
     return locphi <= -120;
@@ -566,7 +566,7 @@ bool l1ct::tdr_regionizer::Regionizer<l1ct::HadCaloObjEmu>::isDuplicate(int locp
 }
 
 template <>
-bool l1ct::tdr_regionizer::Regionizer<l1ct::EmCaloObjEmu>::isDuplicate(int locphi, size_t logicBufIdx) const {
+inline bool l1ct::tdr_regionizer::Regionizer<l1ct::EmCaloObjEmu>::isDuplicate(int locphi, size_t logicBufIdx) const {
   auto odd = logicBufIdx % 2;
   if (odd) {
     return locphi <= -120;