diff --git a/common/fp_lib_table.cpp b/common/fp_lib_table.cpp
index e83c326f9d..e89b85dd8f 100644
--- a/common/fp_lib_table.cpp
+++ b/common/fp_lib_table.cpp
@@ -235,13 +235,13 @@ void FP_LIB_TABLE::Format( OUTPUTFORMATTER* aOutput, int aIndentLevel ) const
 }
 
 
-long long FP_LIB_TABLE::GenLastModifiedChecksum( const wxString* aNickname )
+long long FP_LIB_TABLE::GenerateTimestamp( const wxString* aNickname )
 {
     if( aNickname )
     {
         const FP_LIB_TABLE_ROW* row = FindRow( *aNickname );
         wxASSERT( (PLUGIN*) row->plugin );
-        return row->plugin->GetLibModificationTime( *aNickname ).GetValue().GetValue();
+        return row->plugin->GetLibraryTimestamp();
     }
 
     long long hash = 0;
@@ -250,7 +250,7 @@ long long FP_LIB_TABLE::GenLastModifiedChecksum( const wxString* aNickname )
     {
         const FP_LIB_TABLE_ROW* row = FindRow( nickname );
         wxASSERT( (PLUGIN*) row->plugin );
-        hash += row->plugin->GetLibModificationTime( nickname ).GetValue().GetValue();
+        hash += row->plugin->GetLibraryTimestamp();
     }
 
     return hash;
@@ -297,6 +297,45 @@ const FP_LIB_TABLE_ROW* FP_LIB_TABLE::FindRow( const wxString& aNickname )
 }
 
 
+static void setLibNickname( MODULE* aModule,
+                            const wxString& aNickname, const wxString& aFootprintName )
+{
+    // The library cannot know its own name, because it might have been renamed or moved.
+    // Therefore footprints cannot know their own library nickname when residing in
+    // a footprint library.
+    // Only at this API layer can we tell the footprint about its actual library nickname.
+    if( aModule )
+    {
+        // remove "const"-ness, I really do want to set nickname without
+        // having to copy the LIB_ID and its two strings, twice each.
+        LIB_ID& fpid = (LIB_ID&) aModule->GetFPID();
+
+        // Catch any misbehaving plugin, which should be setting internal footprint name properly:
+        wxASSERT( aFootprintName == fpid.GetLibItemName().wx_str() );
+
+        // and clearing nickname
+        wxASSERT( !fpid.GetLibNickname().size() );
+
+        fpid.SetLibNickname( aNickname );
+    }
+}
+
+
+MODULE* FP_LIB_TABLE::LoadEnumeratedFootprint( const wxString& aNickname,
+                                               const wxString& aFootprintName )
+{
+    const FP_LIB_TABLE_ROW* row = FindRow( aNickname );
+    wxASSERT( (PLUGIN*) row->plugin );
+
+    MODULE* ret = row->plugin->LoadEnumeratedFootprint( row->GetFullURI( true ), aFootprintName,
+                                                        row->GetProperties() );
+
+    setLibNickname( ret, row->GetNickName(), aFootprintName );
+
+    return ret;
+}
+
+
 MODULE* FP_LIB_TABLE::FootprintLoad( const wxString& aNickname, const wxString& aFootprintName )
 {
     const FP_LIB_TABLE_ROW* row = FindRow( aNickname );
@@ -305,24 +344,7 @@ MODULE* FP_LIB_TABLE::FootprintLoad( const wxString& aNickname, const wxString&
     MODULE* ret = row->plugin->FootprintLoad( row->GetFullURI( true ), aFootprintName,
                                               row->GetProperties() );
 
-    // The library cannot know its own name, because it might have been renamed or moved.
-    // Therefore footprints cannot know their own library nickname when residing in
-    // a footprint library.
-    // Only at this API layer can we tell the footprint about its actual library nickname.
-    if( ret )
-    {
-        // remove "const"-ness, I really do want to set nickname without
-        // having to copy the LIB_ID and its two strings, twice each.
-        LIB_ID& fpid = (LIB_ID&) ret->GetFPID();
-
-        // Catch any misbehaving plugin, which should be setting internal footprint name properly:
-        wxASSERT( aFootprintName == fpid.GetLibItemName().wx_str() );
-
-        // and clearing nickname
-        wxASSERT( !fpid.GetLibNickname().size() );
-
-        fpid.SetLibNickname( row->GetNickName() );
-    }
+    setLibNickname( ret, row->GetNickName(), aFootprintName );
 
     return ret;
 }
diff --git a/include/fp_lib_table.h b/include/fp_lib_table.h
index ffa09d3fbf..63ba0a0a2a 100644
--- a/include/fp_lib_table.h
+++ b/include/fp_lib_table.h
@@ -152,10 +152,10 @@ public:
     void FootprintEnumerate( wxArrayString& aFootprintNames, const wxString& aNickname );
 
     /**
-     * Generate a checksum of the last-mod-date of \a aNickname's directory, or a checksum
-     * of all the libraries' directories if \a aNickname is NULL.
+     * Generate a hashed timestamp representing the last-mod-times of the library indicated
+     * by \a aNickname, or all libraries if \a aNickname is NULL.
      */
-    long long GenLastModifiedChecksum( const wxString* aNickname );
+    long long GenerateTimestamp( const wxString* aNickname );
 
     /**
      * Function PrefetchLib
@@ -186,6 +186,13 @@ public:
      */
     MODULE* FootprintLoad( const wxString& aNickname, const wxString& aFootprintName );
 
+    /**
+     * Function LoadEnumeratedFootprint
+     *
+     * a version of FootprintLoad() for use after FootprintEnumerate() for more efficient
+     * cache management.
+     */
+    MODULE* LoadEnumeratedFootprint( const wxString& aNickname, const wxString& aFootprintName );
     /**
      * Enum SAVE_T
      * is the set of return values from FootprintSave() below.
diff --git a/pcbnew/footprint_info_impl.cpp b/pcbnew/footprint_info_impl.cpp
index 37687985aa..c2dff3b0b2 100644
--- a/pcbnew/footprint_info_impl.cpp
+++ b/pcbnew/footprint_info_impl.cpp
@@ -47,8 +47,7 @@ void FOOTPRINT_INFO_IMPL::load()
 
     wxASSERT( fptable );
 
-    std::unique_ptr<MODULE> footprint( fptable->FootprintLoad( m_nickname, m_fpname ) );
-
+    std::unique_ptr<MODULE> footprint( fptable->LoadEnumeratedFootprint( m_nickname, m_fpname ) );
     if( footprint.get() == NULL ) // Should happen only with malformed/broken libraries
     {
         m_pad_count = 0;
@@ -119,7 +118,7 @@ void FOOTPRINT_LIST_IMPL::loader_job()
 bool FOOTPRINT_LIST_IMPL::ReadFootprintFiles( FP_LIB_TABLE* aTable, const wxString* aNickname,
                                               WX_PROGRESS_REPORTER* aProgressReporter )
 {
-    if( aTable->GenLastModifiedChecksum( aNickname ) == m_libraries_last_mod_checksum )
+    if( aTable->GenerateTimestamp( aNickname ) == m_list_timestamp )
         return true;
 
     m_progress_reporter = aProgressReporter;
@@ -167,7 +166,7 @@ bool FOOTPRINT_LIST_IMPL::ReadFootprintFiles( FP_LIB_TABLE* aTable, const wxStri
                     ( _( "Loading incomplete; cancelled by user." ), nullptr, nullptr, 0 ) );
     }
 
-    m_libraries_last_mod_checksum = aTable->GenLastModifiedChecksum( aNickname );
+    m_list_timestamp = aTable->GenerateTimestamp( aNickname );
     m_progress_reporter = nullptr;
 
     return m_errors.empty();
@@ -238,7 +237,7 @@ bool FOOTPRINT_LIST_IMPL::JoinWorkers()
 
                 try
                 {
-                    this->m_lib_table->FootprintEnumerate( fpnames, nickname );
+                    m_lib_table->FootprintEnumerate( fpnames, nickname );
                 }
                 catch( const IO_ERROR& ioe )
                 {
@@ -306,7 +305,7 @@ size_t FOOTPRINT_LIST_IMPL::CountFinished()
 FOOTPRINT_LIST_IMPL::FOOTPRINT_LIST_IMPL() :
     m_loader( nullptr ),
     m_count_finished( 0 ),
-    m_libraries_last_mod_checksum( 0 ),
+    m_list_timestamp( 0 ),
     m_progress_reporter( nullptr ),
     m_cancelled( false )
 {
diff --git a/pcbnew/footprint_info_impl.h b/pcbnew/footprint_info_impl.h
index fcaa76ff75..58976bb325 100644
--- a/pcbnew/footprint_info_impl.h
+++ b/pcbnew/footprint_info_impl.h
@@ -62,7 +62,7 @@ class FOOTPRINT_LIST_IMPL : public FOOTPRINT_LIST
     SYNC_QUEUE<wxString>     m_queue_in;
     SYNC_QUEUE<wxString>     m_queue_out;
     std::atomic_size_t       m_count_finished;
-    long long                m_libraries_last_mod_checksum;
+    long long                m_list_timestamp;
     WX_PROGRESS_REPORTER*    m_progress_reporter;
     std::atomic_bool         m_cancelled;
 
diff --git a/pcbnew/io_mgr.h b/pcbnew/io_mgr.h
index 9435c43712..5e3efcebc2 100644
--- a/pcbnew/io_mgr.h
+++ b/pcbnew/io_mgr.h
@@ -354,12 +354,14 @@ public:
                                      const PROPERTIES* aProperties = NULL );
 
     /**
-     * Return the footprint lib last-mod-time, if available.
+     * Generate a timestamp representing all the files in the library (including the library
+     * directory).
+     * Timestamps should not be considered ordered; they either match or they don't.
      */
-    virtual wxDateTime GetLibModificationTime( const wxString& aLibraryPath ) const
+    virtual long long GetLibraryTimestamp() const
     {
         // Default implementation.
-        return wxDateTime::Now();   // If we don't know then we must assume the worst.
+        return 0;
     }
 
     /**
@@ -408,6 +410,15 @@ public:
     virtual MODULE* FootprintLoad( const wxString& aLibraryPath, const wxString& aFootprintName,
             const PROPERTIES* aProperties = NULL );
 
+    /**
+     * Function LoadEnumeratedFootprint
+     * a version of FootprintLoad() for use after FootprintEnumerate() for more
+     * efficient cache management.
+     */
+    virtual MODULE* LoadEnumeratedFootprint( const wxString& aLibraryPath,
+                                             const wxString& aFootprintName,
+                                             const PROPERTIES* aProperties = NULL );
+
     /**
      * Function FootprintSave
      * will write @a aModule to an existing library located at @a aLibraryPath.
diff --git a/pcbnew/kicad_plugin.cpp b/pcbnew/kicad_plugin.cpp
index d2c0da21d7..e874d5b8a2 100644
--- a/pcbnew/kicad_plugin.cpp
+++ b/pcbnew/kicad_plugin.cpp
@@ -92,7 +92,6 @@ void filterNetClass( const BOARD& aBoard, NETCLASS& aNetClass )
 class FP_CACHE_ITEM
 {
     wxFileName              m_file_name; ///< The the full file name and path of the footprint to cache.
-    wxDateTime              m_mod_time;  ///< The last file modified time stamp.
     std::unique_ptr<MODULE> m_module;
 
 public:
@@ -101,11 +100,7 @@ public:
     wxString    GetName() const { return m_file_name.GetDirs().Last(); }
     wxFileName  GetFileName() const { return m_file_name; }
 
-    /// Tell if the disk content or the lib_path has changed.
-    bool        IsModified() const;
-
     MODULE*     GetModule() const { return m_module.get(); }
-    void        UpdateModificationTime() { m_mod_time = m_file_name.GetModificationTime(); }
 };
 
 
@@ -113,26 +108,6 @@ FP_CACHE_ITEM::FP_CACHE_ITEM( MODULE* aModule, const wxFileName& aFileName ) :
     m_module( aModule )
 {
     m_file_name = aFileName;
-
-    if( m_file_name.FileExists() )
-        m_mod_time = m_file_name.GetModificationTime();
-    else
-        m_mod_time.Now();
-}
-
-
-bool FP_CACHE_ITEM::IsModified() const
-{
-    if( !m_file_name.FileExists() )
-        return false;
-
-    wxLogTrace( traceFootprintLibrary, wxT( "File '%s', m_mod_time %s-%s, file mod time: %s-%s." ),
-                GetChars( m_file_name.GetFullPath() ),
-                GetChars( m_mod_time.FormatDate() ), GetChars( m_mod_time.FormatTime() ),
-                GetChars( m_file_name.GetModificationTime().FormatDate() ),
-                GetChars( m_file_name.GetModificationTime().FormatTime() ) );
-
-    return m_file_name.GetModificationTime() != m_mod_time;
 }
 
 
@@ -145,20 +120,16 @@ class FP_CACHE
 {
     PCB_IO*         m_owner;        /// Plugin object that owns the cache.
     wxFileName      m_lib_path;     /// The path of the library.
-    wxDateTime      m_mod_time;     /// Footprint library path modified time stamp.
     MODULE_MAP      m_modules;      /// Map of footprint file name per MODULE*.
 
-    bool m_represents_non_existant_dir;  // Indicates this cache represents a directory
-                                         // which does not exist. This forces
-                                         // GetLibModificationTime() to return 0 (at least
-                                         // until the directory is found, at which point it
-                                         // will return Now).
+    bool            m_cache_dirty;      // Stored separately because it's expensive
+                                        // to check m_cache_timestamp against file.
+    long long       m_cache_timestamp;  // A timestamp for the footprint file.
 
 public:
     FP_CACHE( PCB_IO* aOwner, const wxString& aLibraryPath );
 
     wxString    GetPath() const { return m_lib_path.GetPath(); }
-    wxDateTime  GetLastModificationTime() const { return m_mod_time; }
     bool        IsWritable() const { return m_lib_path.IsOk() && m_lib_path.IsDirWritable(); }
     MODULE_MAP& GetModules() { return m_modules; }
 
@@ -173,21 +144,19 @@ public:
 
     void Remove( const wxString& aFootprintName );
 
-    wxDateTime GetLibModificationTime() const;
+    /**
+     * Function GetTimestamp
+     * Generate a timestamp representing all source files in the cache (including the
+     * parent directory).
+     * Timestamps should not be considered ordered.  They either match or they don't.
+     */
+    long long GetTimestamp();
 
     /**
      * Function IsModified
-     * check if the footprint cache has been modified relative to \a aLibPath
-     * and \a aFootprintName.
-     *
-     * @param aLibPath is a path to test the current cache library path against.
-     * @param aFootprintName is the footprint name in the cache to test.  If the footprint
-     *                       name is empty, the all the footprint files in the library are
-     *                       checked to see if they have been modified.
-     * @return true if the cache has been modified.
+     * Return true if the cache is not up-to-date.
      */
-    bool IsModified( const wxString& aLibPath,
-                     const wxString& aFootprintName = wxEmptyString ) const;
+    bool IsModified();
 
     /**
      * Function IsPath
@@ -206,30 +175,18 @@ public:
 
 
 FP_CACHE::FP_CACHE( PCB_IO* aOwner, const wxString& aLibraryPath )
-    : m_mod_time( 0.0 )
 {
     m_owner = aOwner;
     m_lib_path.SetPath( aLibraryPath );
-    m_represents_non_existant_dir = false;
-}
-
-
-wxDateTime FP_CACHE::GetLibModificationTime() const
-{
-    if( !m_lib_path.DirExists() )
-    {
-        if( m_represents_non_existant_dir )
-            return wxDateTime( 0.0 );
-        else
-            return wxDateTime::Now();
-    }
-
-    return m_lib_path.GetModificationTime();
+    m_cache_timestamp = 0;
+    m_cache_dirty = true;
 }
 
 
 void FP_CACHE::Save()
 {
+    m_cache_timestamp = 0;
+
     if( !m_lib_path.DirExists() && !m_lib_path.Mkdir() )
     {
         THROW_IO_ERROR( wxString::Format( _( "Cannot create footprint library path \"%s\"" ),
@@ -246,9 +203,6 @@ void FP_CACHE::Save()
     {
         wxFileName fn = it->second->GetFileName();
 
-        if( fn.FileExists() && !it->second->IsModified() )
-            continue;
-
         wxString tempFileName =
 #ifdef USE_TMP_FILE
         fn.CreateTempFileName( fn.GetPath() );
@@ -284,21 +238,22 @@ void FP_CACHE::Save()
             THROW_IO_ERROR( msg );
         }
 #endif
-        it->second->UpdateModificationTime();
-        m_mod_time = GetLibModificationTime();
+        m_cache_timestamp += fn.GetModificationTime().GetValue().GetValue();
     }
+
+    m_cache_timestamp += m_lib_path.GetModificationTime().GetValue().GetValue();
+    m_cache_dirty = false;
 }
 
 
 void FP_CACHE::Load()
-{
-    m_represents_non_existant_dir = false;
-
+{    
     wxDir dir( m_lib_path.GetPath() );
 
     if( !dir.IsOpened() )
     {
-        m_represents_non_existant_dir = true;
+        m_cache_timestamp = 0;
+        m_cache_dirty = false;
 
         wxString msg = wxString::Format(
                 _( "Footprint library path \"%s\" does not exist" ),
@@ -307,6 +262,11 @@ void FP_CACHE::Load()
 
         THROW_IO_ERROR( msg );
     }
+    else
+    {
+        m_cache_timestamp = m_lib_path.GetModificationTime().GetValue().GetValue();
+        m_cache_dirty = false;
+    }
 
     wxString fpFileName;
     wxString wildcard = wxT( "*." ) + KiCadFootprintFileExtension;
@@ -334,6 +294,8 @@ void FP_CACHE::Load()
 
                 footprint->SetFPID( LIB_ID( fpName ) );
                 m_modules.insert( fpName, new FP_CACHE_ITEM( footprint, fullPath ) );
+
+                m_cache_timestamp += fullPath.GetModificationTime().GetValue().GetValue();
             }
             catch( const IO_ERROR& ioe )
             {
@@ -344,11 +306,6 @@ void FP_CACHE::Load()
             }
         } while( dir.GetNext( &fpFileName ) );
 
-        // Remember the file modification time of library file when the
-        // cache snapshot was made, so that in a networked environment we will
-        // reload the cache as needed.
-        m_mod_time = GetLibModificationTime();
-
         if( !cacheError.IsEmpty() )
             THROW_IO_ERROR( cacheError );
     }
@@ -386,9 +343,41 @@ bool FP_CACHE::IsPath( const wxString& aPath ) const
 }
 
 
-bool FP_CACHE::IsModified( const wxString& aLibPath, const wxString& aFootprintName ) const
+bool FP_CACHE::IsModified()
 {
-    return GetLibModificationTime() > m_mod_time;
+    if( m_cache_dirty )
+        return true;
+    else
+        return GetTimestamp() != m_cache_timestamp;
+}
+
+
+long long FP_CACHE::GetTimestamp()
+{
+    // Avoid expensive GetModificationTime checks if we already know we're dirty
+    if( m_cache_dirty )
+        return wxDateTime::Now().GetValue().GetValue();
+
+    long long files_timestamp = 0;
+
+    if( m_lib_path.DirExists() )
+    {
+        files_timestamp = m_lib_path.GetModificationTime().GetValue().GetValue();
+
+        for( MODULE_CITER it = m_modules.begin();  it != m_modules.end();  ++it )
+        {
+            wxFileName moduleFile = it->second->GetFileName();
+            if( moduleFile.FileExists() )
+                files_timestamp += moduleFile.GetModificationTime().GetValue().GetValue();
+        }
+    }
+
+    // If the new timestamp doesn't match the cache timestamp, then save ourselves the
+    // expensive calls next time
+    if( m_cache_timestamp != files_timestamp )
+        m_cache_dirty = true;
+
+    return files_timestamp;
 }
 
 
@@ -1955,9 +1944,9 @@ void PCB_IO::init( const PROPERTIES* aProperties )
 }
 
 
-void PCB_IO::cacheLib( const wxString& aLibraryPath, const wxString& aFootprintName )
+void PCB_IO::validateCache( const wxString& aLibraryPath )
 {
-    if( !m_cache || m_cache->IsModified( aLibraryPath, aFootprintName ) )
+    if( !m_cache || m_cache->IsModified() )
     {
         // a spectacular episode in memory management:
         delete m_cache;
@@ -1980,7 +1969,7 @@ void PCB_IO::FootprintEnumerate( wxArrayString&    aFootprintNames,
 
     try
     {
-        cacheLib( aLibraryPath );
+        validateCache( aLibraryPath );
     }
     catch( const IO_ERROR& ioe )
     {
@@ -2002,15 +1991,14 @@ void PCB_IO::FootprintEnumerate( wxArrayString&    aFootprintNames,
 }
 
 
-MODULE* PCB_IO::FootprintLoad( const wxString& aLibraryPath, const wxString& aFootprintName,
-                               const PROPERTIES* aProperties )
+MODULE* PCB_IO::LoadEnumeratedFootprint( const wxString& aLibraryPath,
+                                         const wxString& aFootprintName,
+                                         const PROPERTIES* aProperties )
 {
     LOCALE_IO   toggle;     // toggles on, then off, the C locale.
 
     init( aProperties );
 
-    cacheLib( aLibraryPath, aFootprintName );
-
     const MODULE_MAP& mods = m_cache->GetModules();
 
     MODULE_CITER it = mods.find( aFootprintName );
@@ -2025,6 +2013,17 @@ MODULE* PCB_IO::FootprintLoad( const wxString& aLibraryPath, const wxString& aFo
 }
 
 
+MODULE* PCB_IO::FootprintLoad( const wxString& aLibraryPath, const wxString& aFootprintName,
+                               const PROPERTIES* aProperties )
+{
+    LOCALE_IO   toggle;     // toggles on, then off, the C locale.
+
+    validateCache( aLibraryPath );
+
+    return LoadEnumeratedFootprint( aLibraryPath, aFootprintName, aProperties );
+}
+
+
 void PCB_IO::FootprintSave( const wxString& aLibraryPath, const MODULE* aFootprint,
                             const PROPERTIES* aProperties )
 {
@@ -2036,7 +2035,7 @@ void PCB_IO::FootprintSave( const wxString& aLibraryPath, const MODULE* aFootpri
     // called for saving into a library path.
     m_ctl = CTL_FOR_LIBRARY;
 
-    cacheLib( aLibraryPath );
+    validateCache( aLibraryPath );
 
     if( !m_cache->IsWritable() )
     {
@@ -2103,7 +2102,7 @@ void PCB_IO::FootprintDelete( const wxString& aLibraryPath, const wxString& aFoo
 
     init( aProperties );
 
-    cacheLib( aLibraryPath );
+    validateCache( aLibraryPath );
 
     if( !m_cache->IsWritable() )
     {
@@ -2116,12 +2115,13 @@ void PCB_IO::FootprintDelete( const wxString& aLibraryPath, const wxString& aFoo
 
 
 
-wxDateTime PCB_IO::GetLibModificationTime( const wxString& aLibraryPath ) const
+long long PCB_IO::GetLibraryTimestamp() const
 {
+    // If we have not cache, return a number which won't match any stored timestamps
     if( !m_cache )
-        return wxDateTime::Now();     // force a load
+        return wxDateTime::Now().GetValue().GetValue();
 
-    return m_cache->GetLibModificationTime();
+    return m_cache->GetTimestamp();
 }
 
 
@@ -2226,7 +2226,7 @@ bool PCB_IO::IsFootprintLibWritable( const wxString& aLibraryPath )
 
     init( NULL );
 
-    cacheLib( aLibraryPath );
+    validateCache( aLibraryPath );
 
     return m_cache->IsWritable();
 }
diff --git a/pcbnew/kicad_plugin.h b/pcbnew/kicad_plugin.h
index c5ae9a13a0..c95459070c 100644
--- a/pcbnew/kicad_plugin.h
+++ b/pcbnew/kicad_plugin.h
@@ -121,6 +121,9 @@ public:
     void FootprintEnumerate( wxArrayString& aFootprintNames, const wxString& aLibraryPath,
             const PROPERTIES* aProperties = NULL ) override;
 
+    MODULE* LoadEnumeratedFootprint( const wxString& aLibraryPath, const wxString& aFootprintName,
+            const PROPERTIES* aProperties = NULL ) override;
+
     MODULE* FootprintLoad( const wxString& aLibraryPath, const wxString& aFootprintName,
             const PROPERTIES* aProperties = NULL ) override;
 
@@ -130,7 +133,7 @@ public:
     void FootprintDelete( const wxString& aLibraryPath, const wxString& aFootprintName,
                           const PROPERTIES* aProperties = NULL ) override;
 
-    wxDateTime GetLibModificationTime( const wxString& aLibraryPath ) const override;
+    long long GetLibraryTimestamp() const override;
 
     void FootprintLibCreate( const wxString& aLibraryPath, const PROPERTIES* aProperties = NULL) override;
 
@@ -188,8 +191,7 @@ protected:
     NETINFO_MAPPING*    m_mapping;  ///< mapping for net codes, so only not empty net codes
                                     ///< are stored with consecutive integers as net codes
 
-    /// we only cache one footprint library, this determines which one.
-    void cacheLib( const wxString& aLibraryPath, const wxString& aFootprintName = wxEmptyString );
+    void validateCache( const wxString& aLibraryPath );
 
     void init( const PROPERTIES* aProperties );
 
diff --git a/pcbnew/load_select_footprint.cpp b/pcbnew/load_select_footprint.cpp
index 8212e66268..355cb79aad 100644
--- a/pcbnew/load_select_footprint.cpp
+++ b/pcbnew/load_select_footprint.cpp
@@ -574,7 +574,7 @@ void FOOTPRINT_EDIT_FRAME::OnSaveLibraryAs( wxCommandEvent& aEvent )
 
         for( unsigned i = 0;  i < mods.size();  ++i )
         {
-            std::unique_ptr<MODULE> m( cur->FootprintLoad( curLibPath, mods[i] ) );
+            std::unique_ptr<MODULE> m( cur->LoadEnumeratedFootprint( curLibPath, mods[i] ) );
             dst->FootprintSave( dstLibPath, m.get() );
 
             msg = wxString::Format( _( "Footprint \"%s\" saved" ),
diff --git a/pcbnew/plugin.cpp b/pcbnew/plugin.cpp
index 6f37e347da..af75fefce5 100644
--- a/pcbnew/plugin.cpp
+++ b/pcbnew/plugin.cpp
@@ -73,6 +73,15 @@ void PLUGIN::PrefetchLib( const wxString& aLibraryPath, const PROPERTIES* aPrope
 }
 
 
+MODULE* PLUGIN::LoadEnumeratedFootprint( const wxString& aLibraryPath,
+                                         const wxString& aFootprintName,
+                                         const PROPERTIES* aProperties )
+{
+    // default implementation
+    return FootprintLoad( aLibraryPath, aFootprintName, aProperties );
+}
+
+
 MODULE* PLUGIN::FootprintLoad( const wxString& aLibraryPath, const wxString& aFootprintName,
                                     const PROPERTIES* aProperties )
 {