diff --git a/src/iexamine_elevator.cpp b/src/iexamine_elevator.cpp
index 7a01baa94c14..2e24e96f655f 100644
--- a/src/iexamine_elevator.cpp
+++ b/src/iexamine_elevator.cpp
@@ -19,7 +19,8 @@ namespace
 
 /// poor person's https://en.cppreference.com/w/cpp/utility/optional/and_then
 template <typename T, typename Fn>
-auto and_then( std::optional<T> const &opt, Fn &&f ) -> std::optional<std::invoke_result_t<Fn, T>>
+inline auto and_then( std::optional<T> const &opt, Fn &&f )
+-> std::optional<std::invoke_result_t<Fn, T>>
 {
     if( opt ) {
         return std::optional{f( *opt )};
@@ -29,7 +30,7 @@ auto and_then( std::optional<T> const &opt, Fn &&f ) -> std::optional<std::invok
 
 // still not sure whether there's a utility function for this
 // NOLINTNEXTLINE(bugprone-easily-swappable-parameters)
-auto move_item( map &here, const tripoint &src, const tripoint &dest ) -> void
+inline auto move_item( map &here, const tripoint &src, const tripoint &dest ) -> void
 {
     map_stack items = here.i_at( src );
     for( auto it = items.begin(); it != items.end(); ) {
@@ -43,7 +44,7 @@ namespace elevator
 
 using tiles = std::vector<tripoint>;
 
-auto here( const Character &you ) -> elevator::tiles
+inline auto here( const Character &you ) -> elevator::tiles
 {
     const auto &here = get_map();
     const auto &points = closest_points_first( you.pos(), SEEX - 1 );
@@ -57,10 +58,10 @@ auto here( const Character &you ) -> elevator::tiles
     return tiles;
 }
 
-auto dest( const elevator::tiles &elevator_here,
-           const tripoint &sm_orig,
-           int turns,
-           int movez ) -> elevator::tiles
+inline auto dest( const elevator::tiles &elevator_here,
+                  const tripoint &sm_orig,
+                  int turns,
+                  int movez ) -> elevator::tiles
 {
     elevator::tiles tiles;
     std::transform( elevator_here.begin(), elevator_here.end(), std::back_inserter( tiles ),
@@ -73,7 +74,7 @@ auto dest( const elevator::tiles &elevator_here,
 
 /// allow using misaligned elevators.
 /// doesn't prevent you being stuck in the wall tho cause i was lazy
-auto find_elevators_nearby( const tripoint &pos ) -> std::optional<tripoint>
+inline auto find_elevators_nearby( const tripoint &pos ) -> std::optional<tripoint>
 {
     constexpr int max_misalign = 3;
     map &here = get_map();
@@ -86,8 +87,8 @@ auto find_elevators_nearby( const tripoint &pos ) -> std::optional<tripoint>
     return {};
 }
 
-auto choose_floor( const tripoint &examp, const tripoint_abs_omt &this_omt,
-                   const tripoint &sm_orig ) -> int
+inline auto choose_floor( const tripoint &examp, const tripoint_abs_omt &this_omt,
+                          const tripoint &sm_orig ) -> int
 {
     constexpr int retval_offset = 10000; // workaround for uilist retval autoassign when retval == -1
     const auto this_floor = _( " (this floor)" );
@@ -115,7 +116,8 @@ auto choose_floor( const tripoint &examp, const tripoint_abs_omt &this_omt,
 
 enum class overlap_status { outside, inside, overlap };
 
-auto vehicle_status( const wrapped_vehicle &veh, const elevator::tiles &tiles ) -> overlap_status
+inline auto vehicle_status( const wrapped_vehicle &veh,
+                            const elevator::tiles &tiles ) -> overlap_status
 {
     const auto &ps = veh.v->get_all_parts();
     const int all_vparts_count = ps.part_count();
@@ -139,7 +141,7 @@ struct elevator_vehicles {
     std::vector<vehicle *> v;
 };
 
-auto vehicles_on( const elevator::tiles &tiles ) -> elevator_vehicles
+inline auto vehicles_on( const elevator::tiles &tiles ) -> elevator_vehicles
 {
     const VehicleList vehs = get_map().get_vehicles();
     std::vector<vehicle *> ret;
@@ -156,13 +158,13 @@ auto vehicles_on( const elevator::tiles &tiles ) -> elevator_vehicles
     return { false, ret };
 }
 
-auto warn_blocking( const elevator_vehicles &vehs, std::string_view location ) -> void
+inline auto warn_blocking( const elevator_vehicles &vehs, std::string_view location ) -> void
 {
     const auto &first_veh_name = vehs.v.front()->name;
     popup( string_format( _( "%1$s %2$s is blocking the elevator." ), first_veh_name, location ) );
 }
 
-auto move_creatures_away( const elevator::tiles &dest ) -> void
+inline auto move_creatures_away( const elevator::tiles &dest ) -> void
 {
     map &here = get_map();
 
@@ -189,7 +191,8 @@ auto move_creatures_away( const elevator::tiles &dest ) -> void
     }
 }
 
-auto move_items( const elevator::tiles from, const elevator::tiles dest ) -> void
+// NOLINTNEXTLINE(bugprone-easily-swappable-parameters)
+inline auto move_items( const elevator::tiles from, const elevator::tiles dest ) -> void
 {
     map &here = get_map();
 
@@ -199,7 +202,7 @@ auto move_items( const elevator::tiles from, const elevator::tiles dest ) -> voi
     }
 }
 
-auto move_creatures( const elevator::tiles from, const elevator::tiles dest ) -> void
+inline auto move_creatures( const elevator::tiles from, const elevator::tiles dest ) -> void
 {
     for( Creature &critter : g->all_creatures() ) {
         const auto eit = std::find( from.cbegin(), from.cend(), critter.pos() );
@@ -209,8 +212,8 @@ auto move_creatures( const elevator::tiles from, const elevator::tiles dest ) ->
     }
 }
 
-auto move_vehicles( const elevator_vehicles &vehs, const tripoint &sm_orig, int movez,
-                    int turns ) -> void
+inline auto move_vehicles( const elevator_vehicles &vehs, const tripoint &sm_orig, int movez,
+                           int turns ) -> void
 {
     map &here = get_map();
 
@@ -224,7 +227,7 @@ auto move_vehicles( const elevator_vehicles &vehs, const tripoint &sm_orig, int
     here.reset_vehicle_cache();
 }
 
-auto move_player( player &p, const int movez, tripoint_abs_ms old_abs_pos ) -> void
+inline auto move_player( player &p, const int movez, tripoint_abs_ms old_abs_pos ) -> void
 {
     map &here = get_map();