diff --git a/macosx/AddMagnetWindowController.mm b/macosx/AddMagnetWindowController.mm
index adb3b6235..5d07d30c1 100644
--- a/macosx/AddMagnetWindowController.mm
+++ b/macosx/AddMagnetWindowController.mm
@@ -13,7 +13,7 @@
 #define POPUP_PRIORITY_NORMAL 1
 #define POPUP_PRIORITY_LOW 2
 
-@interface AddMagnetWindowController (Private)
+@interface AddMagnetWindowController ()
 
 - (void)confirmAdd;
 
@@ -268,10 +268,6 @@
     }
 }
 
-@end
-
-@implementation AddMagnetWindowController (Private)
-
 - (void)confirmAdd
 {
     [fTorrent setGroupValue:fGroupValue determinationType:fGroupDeterminationType];
diff --git a/macosx/AddWindowController.mm b/macosx/AddWindowController.mm
index 16b13f45e..15eb6219b 100644
--- a/macosx/AddWindowController.mm
+++ b/macosx/AddWindowController.mm
@@ -16,7 +16,7 @@
 #define POPUP_PRIORITY_NORMAL 1
 #define POPUP_PRIORITY_LOW 2
 
-@interface AddWindowController (Private)
+@interface AddWindowController ()
 
 - (void)updateFiles;
 
@@ -324,10 +324,6 @@
     }
 }
 
-@end
-
-@implementation AddWindowController (Private)
-
 - (void)updateFiles
 {
     [fTorrent update];
diff --git a/macosx/BadgeView.mm b/macosx/BadgeView.mm
index e9746e5b9..8fdb5f7be 100644
--- a/macosx/BadgeView.mm
+++ b/macosx/BadgeView.mm
@@ -7,7 +7,7 @@
 
 #define BETWEEN_PADDING 2.0
 
-@interface BadgeView (Private)
+@interface BadgeView ()
 
 - (void)badge:(NSImage*)badge string:(NSString*)string atHeight:(CGFloat)height adjustForQuit:(BOOL)quit;
 
@@ -78,10 +78,6 @@
     }
 }
 
-@end
-
-@implementation BadgeView (Private)
-
 - (void)badge:(NSImage*)badge string:(NSString*)string atHeight:(CGFloat)height adjustForQuit:(BOOL)quit
 {
     if (!fAttributes)
diff --git a/macosx/BlocklistDownloader.mm b/macosx/BlocklistDownloader.mm
index 713fba41f..06b6c6457 100644
--- a/macosx/BlocklistDownloader.mm
+++ b/macosx/BlocklistDownloader.mm
@@ -7,7 +7,7 @@
 #import "BlocklistScheduler.h"
 #import "Controller.h"
 
-@interface BlocklistDownloader (Private)
+@interface BlocklistDownloader ()
 
 - (void)startDownload;
 - (void)decompressFrom:(NSURL*)file to:(NSURL*)destination error:(NSError**)error;
@@ -158,10 +158,6 @@ didFinishDownloadingToURL:(NSURL *)location
     });
 }
 
-@end
-
-@implementation BlocklistDownloader (Private)
-
 - (void)startDownload
 {
     fState = BLOCKLIST_DL_START;
diff --git a/macosx/BlocklistDownloaderViewController.mm b/macosx/BlocklistDownloaderViewController.mm
index 07fdeb5c9..6ee6fe7dc 100644
--- a/macosx/BlocklistDownloaderViewController.mm
+++ b/macosx/BlocklistDownloaderViewController.mm
@@ -7,7 +7,7 @@
 #import "PrefsController.h"
 #import "NSStringAdditions.h"
 
-@interface BlocklistDownloaderViewController (Private)
+@interface BlocklistDownloaderViewController ()
 
 - (instancetype)initWithPrefsController:(PrefsController*)prefsController;
 - (void)startDownload;
@@ -108,10 +108,6 @@ BlocklistDownloaderViewController* fBLViewController = nil;
     }];
 }
 
-@end
-
-@implementation BlocklistDownloaderViewController (Private)
-
 - (instancetype)initWithPrefsController:(PrefsController*)prefsController
 {
     if ((self = [super init]))
diff --git a/macosx/BlocklistScheduler.mm b/macosx/BlocklistScheduler.mm
index 2d7d56014..f425ed2ca 100644
--- a/macosx/BlocklistScheduler.mm
+++ b/macosx/BlocklistScheduler.mm
@@ -11,7 +11,7 @@
 //update one week after previous update
 #define FULL_WAIT (60 * 60 * 24 * 7)
 
-@interface BlocklistScheduler (Private)
+@interface BlocklistScheduler ()
 
 - (void)runUpdater;
 
@@ -71,10 +71,6 @@ BlocklistScheduler* fScheduler = nil;
     fTimer = nil;
 }
 
-@end
-
-@implementation BlocklistScheduler (Private)
-
 - (void)runUpdater
 {
     fTimer = nil;
diff --git a/macosx/CreatorWindowController.mm b/macosx/CreatorWindowController.mm
index 542bee86d..484a7e994 100644
--- a/macosx/CreatorWindowController.mm
+++ b/macosx/CreatorWindowController.mm
@@ -14,7 +14,7 @@
 #define TRACKER_ADD_TAG 0
 #define TRACKER_REMOVE_TAG 1
 
-@interface CreatorWindowController (Private)
+@interface CreatorWindowController ()
 
 + (NSURL*)chooseFile;
 
@@ -478,10 +478,6 @@ NSMutableSet* creatorWindowControllerSet = nil;
     }
 }
 
-@end
-
-@implementation CreatorWindowController (Private)
-
 - (void)updateLocationField
 {
     NSString* pathString = fLocation.path;
diff --git a/macosx/DragOverlayWindow.mm b/macosx/DragOverlayWindow.mm
index f720be643..7177d3d59 100644
--- a/macosx/DragOverlayWindow.mm
+++ b/macosx/DragOverlayWindow.mm
@@ -9,7 +9,7 @@
 #include <libtransmission/transmission.h>
 #include <libtransmission/torrent-metainfo.h>
 
-@interface DragOverlayWindow (Private)
+@interface DragOverlayWindow ()
 
 - (void)resizeWindow;
 
@@ -171,10 +171,6 @@
     }
 }
 
-@end
-
-@implementation DragOverlayWindow (Private)
-
 - (void)resizeWindow
 {
     [self setFrame:self.parentWindow.frame display:NO];
diff --git a/macosx/FileListNode.mm b/macosx/FileListNode.mm
index 8e175c00d..dd40b9aa0 100644
--- a/macosx/FileListNode.mm
+++ b/macosx/FileListNode.mm
@@ -4,7 +4,7 @@
 
 #import "FileListNode.h"
 
-@interface FileListNode (Private)
+@interface FileListNode ()
 
 - (instancetype)initWithFolder:(BOOL)isFolder name:(NSString*)name path:(NSString*)path torrent:(Torrent*)torrent;
 
@@ -137,10 +137,6 @@
     return NO;
 }
 
-@end
-
-@implementation FileListNode (Private)
-
 - (instancetype)initWithFolder:(BOOL)isFolder name:(NSString*)name path:(NSString*)path torrent:(Torrent*)torrent
 {
     if ((self = [super init]))
diff --git a/macosx/FileNameCell.mm b/macosx/FileNameCell.mm
index 71c090fca..f4597f1b6 100644
--- a/macosx/FileNameCell.mm
+++ b/macosx/FileNameCell.mm
@@ -20,7 +20,7 @@
 #define PADDING_BETWEEN_NAME_AND_FOLDER_STATUS 4.0
 #define PADDING_EXPANSION_FRAME 2.0
 
-@interface FileNameCell (Private)
+@interface FileNameCell ()
 
 - (NSRect)rectForTitleWithString:(NSAttributedString*)string inBounds:(NSRect)bounds;
 - (NSRect)rectForStatusWithString:(NSAttributedString*)string withTitleRect:(NSRect)titleRect inBounds:(NSRect)bounds;
@@ -142,10 +142,6 @@
     [titleString drawInRect:cellFrame];
 }
 
-@end
-
-@implementation FileNameCell (Private)
-
 - (NSRect)rectForTitleWithString:(NSAttributedString*)string inBounds:(NSRect)bounds
 {
     NSSize const titleSize = [string size];
diff --git a/macosx/FileOutlineController.mm b/macosx/FileOutlineController.mm
index 769ca5a31..8172e7978 100644
--- a/macosx/FileOutlineController.mm
+++ b/macosx/FileOutlineController.mm
@@ -27,7 +27,7 @@ typedef NS_ENUM(unsigned int, filePriorityMenuTag) { //
     FILE_PRIORITY_LOW_TAG
 };
 
-@interface FileOutlineController (Private)
+@interface FileOutlineController ()
 
 @property(nonatomic, readonly) NSMenu* menu;
 
@@ -598,10 +598,6 @@ typedef NS_ENUM(unsigned int, filePriorityMenuTag) { //
     return YES;
 }
 
-@end
-
-@implementation FileOutlineController (Private)
-
 - (NSMenu*)menu
 {
     NSMenu* menu = [[NSMenu alloc] initWithTitle:@"File Outline Menu"];
diff --git a/macosx/FilterBarController.mm b/macosx/FilterBarController.mm
index 53f3e8255..b03649564 100644
--- a/macosx/FilterBarController.mm
+++ b/macosx/FilterBarController.mm
@@ -13,7 +13,7 @@
 #define SEARCH_MIN_WIDTH 48.0
 #define SEARCH_MAX_WIDTH 95.0
 
-@interface FilterBarController (Private)
+@interface FilterBarController ()
 
 - (void)resizeBar;
 - (void)updateGroupsButton;
@@ -363,10 +363,6 @@
     return YES;
 }
 
-@end
-
-@implementation FilterBarController (Private)
-
 - (void)resizeBar
 {
     //replace all buttons
diff --git a/macosx/GroupsController.mm b/macosx/GroupsController.mm
index e9a1ca9c9..619d55aa6 100644
--- a/macosx/GroupsController.mm
+++ b/macosx/GroupsController.mm
@@ -8,7 +8,7 @@
 #define ICON_WIDTH 16.0
 #define ICON_WIDTH_SMALL 12.0
 
-@interface GroupsController (Private)
+@interface GroupsController ()
 
 - (void)saveGroups;
 
@@ -335,10 +335,6 @@ GroupsController* fGroupsInstance = nil;
     return -1;
 }
 
-@end
-
-@implementation GroupsController (Private)
-
 - (void)saveGroups
 {
     //don't archive the icon
diff --git a/macosx/GroupsPrefsController.mm b/macosx/GroupsPrefsController.mm
index b8247d922..e0c098b8c 100644
--- a/macosx/GroupsPrefsController.mm
+++ b/macosx/GroupsPrefsController.mm
@@ -21,7 +21,7 @@
 
 @end
 
-@interface GroupsPrefsController (Private)
+@interface GroupsPrefsController ()
 
 - (void)updateSelectedGroup;
 - (void)refreshCustomLocationWithSingleGroup;
@@ -333,10 +333,6 @@
     ruleEditorScrollView.hasVerticalScroller = requiredRowCount > maxVisibleRowCount;
 }
 
-@end
-
-@implementation GroupsPrefsController (Private)
-
 - (void)updateSelectedGroup
 {
     [fAddRemoveControl setEnabled:fTableView.numberOfSelectedRows > 0 forSegment:REMOVE_TAG];
diff --git a/macosx/InfoActivityViewController.mm b/macosx/InfoActivityViewController.mm
index 59af890de..5c84ab63a 100644
--- a/macosx/InfoActivityViewController.mm
+++ b/macosx/InfoActivityViewController.mm
@@ -14,7 +14,7 @@
 #define PIECES_CONTROL_PROGRESS 0
 #define PIECES_CONTROL_AVAILABLE 1
 
-@interface InfoActivityViewController (Private)
+@interface InfoActivityViewController ()
 
 - (void)setupInfo;
 
@@ -246,10 +246,6 @@
     [fPiecesView clearView];
 }
 
-@end
-
-@implementation InfoActivityViewController (Private)
-
 - (void)setupInfo
 {
     NSUInteger const count = fTorrents.count;
diff --git a/macosx/InfoFileViewController.mm b/macosx/InfoFileViewController.mm
index 365c0e6d0..a18e6b7e0 100644
--- a/macosx/InfoFileViewController.mm
+++ b/macosx/InfoFileViewController.mm
@@ -8,7 +8,7 @@
 #import "FileOutlineView.h"
 #import "Torrent.h"
 
-@interface InfoFileViewController (Private)
+@interface InfoFileViewController ()
 
 - (void)setupInfo;
 
@@ -191,10 +191,6 @@
     return NSZeroRect;
 }
 
-@end
-
-@implementation InfoFileViewController (Private)
-
 - (void)setupInfo
 {
     fFileFilterField.stringValue = @"";
diff --git a/macosx/InfoGeneralViewController.mm b/macosx/InfoGeneralViewController.mm
index c92e95119..79643f63b 100644
--- a/macosx/InfoGeneralViewController.mm
+++ b/macosx/InfoGeneralViewController.mm
@@ -6,7 +6,7 @@
 #import "NSStringAdditions.h"
 #import "Torrent.h"
 
-@interface InfoGeneralViewController (Private)
+@interface InfoGeneralViewController ()
 
 - (void)setupInfo;
 
@@ -127,10 +127,6 @@
     [NSWorkspace.sharedWorkspace activateFileViewerSelectingURLs:@[ file ]];
 }
 
-@end
-
-@implementation InfoGeneralViewController (Private)
-
 - (void)setupInfo
 {
     if (fTorrents.count == 1)
diff --git a/macosx/InfoPeersViewController.mm b/macosx/InfoPeersViewController.mm
index f01aa004a..340c6896b 100644
--- a/macosx/InfoPeersViewController.mm
+++ b/macosx/InfoPeersViewController.mm
@@ -15,7 +15,7 @@
 #define ANIMATION_ID_KEY @"animationId"
 #define WEB_SEED_ANIMATION_ID @"webSeed"
 
-@interface InfoPeersViewController (Private)<CAAnimationDelegate>
+@interface InfoPeersViewController ()<CAAnimationDelegate>
 
 - (void)setupInfo;
 
@@ -506,10 +506,6 @@
     fWebSeedTable.enclosingScrollView.hidden = finished && fWebSeedTableTopConstraint.constant < 0;
 }
 
-@end
-
-@implementation InfoPeersViewController (Private)
-
 - (void)setupInfo
 {
     __block BOOL hasWebSeeds = NO;
diff --git a/macosx/InfoTrackersViewController.mm b/macosx/InfoTrackersViewController.mm
index db0ec3468..a7a89135c 100644
--- a/macosx/InfoTrackersViewController.mm
+++ b/macosx/InfoTrackersViewController.mm
@@ -14,7 +14,7 @@
 #define TRACKER_ADD_TAG 0
 #define TRACKER_REMOVE_TAG 1
 
-@interface InfoTrackersViewController (Private)
+@interface InfoTrackersViewController ()
 
 - (void)setupInfo;
 
@@ -262,10 +262,6 @@
     }
 }
 
-@end
-
-@implementation InfoTrackersViewController (Private)
-
 - (void)setupInfo
 {
     NSUInteger const numberSelected = fTorrents.count;
diff --git a/macosx/MessageWindowController.mm b/macosx/MessageWindowController.mm
index e82b26317..631e6b874 100644
--- a/macosx/MessageWindowController.mm
+++ b/macosx/MessageWindowController.mm
@@ -17,7 +17,7 @@
 
 #define UPDATE_SECONDS 0.75
 
-@interface MessageWindowController (Private)
+@interface MessageWindowController ()
 
 - (void)resizeColumn;
 - (BOOL)shouldIncludeMessageForFilter:(NSString*)filterString message:(NSDictionary*)message;
@@ -418,10 +418,6 @@
     }];
 }
 
-@end
-
-@implementation MessageWindowController (Private)
-
 - (void)resizeColumn
 {
     [fMessageTable noteHeightOfRowsWithIndexesChanged:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, fMessageTable.numberOfRows)]];
diff --git a/macosx/PortChecker.mm b/macosx/PortChecker.mm
index a18b7c100..83f97bea8 100644
--- a/macosx/PortChecker.mm
+++ b/macosx/PortChecker.mm
@@ -7,7 +7,7 @@
 #define CHECKER_URL(port) [NSString stringWithFormat:@"https://portcheck.transmissionbt.com/%ld", port]
 #define CHECK_FIRE 3.0
 
-@interface PortChecker (Private)
+@interface PortChecker ()
 
 - (void)startProbe:(NSTimer*)timer;
 
@@ -99,10 +99,6 @@
     }
 }
 
-@end
-
-@implementation PortChecker (Private)
-
 - (void)startProbe:(NSTimer*)timer
 {
     fTimer = nil;
diff --git a/macosx/PrefsController.mm b/macosx/PrefsController.mm
index f13559fed..a9914cafc 100644
--- a/macosx/PrefsController.mm
+++ b/macosx/PrefsController.mm
@@ -39,7 +39,7 @@
 
 #define WEBUI_URL @"http://localhost:%ld/"
 
-@interface PrefsController (Private)
+@interface PrefsController ()
 
 - (void)setPrefView:(id)sender;
 
@@ -1491,10 +1491,6 @@
     [NSNotificationCenter.defaultCenter postNotificationName:@"UpdateGlobalOptions" object:nil];
 }
 
-@end
-
-@implementation PrefsController (Private)
-
 - (void)setPrefView:(id)sender
 {
     NSString* identifier;
diff --git a/macosx/StatsWindowController.mm b/macosx/StatsWindowController.mm
index 1964d4109..0a328887a 100644
--- a/macosx/StatsWindowController.mm
+++ b/macosx/StatsWindowController.mm
@@ -9,7 +9,7 @@
 
 #define UPDATE_SECONDS 1.0
 
-@interface StatsWindowController (Private)
+@interface StatsWindowController ()
 
 - (void)updateStats;
 
@@ -152,10 +152,6 @@ tr_session* fLib = NULL;
     return @"StatsWindow";
 }
 
-@end
-
-@implementation StatsWindowController (Private)
-
 - (void)updateStats
 {
     tr_session_stats statsAll, statsSession;
diff --git a/macosx/StatusBarController.mm b/macosx/StatusBarController.mm
index 8303d0249..60aac3263 100644
--- a/macosx/StatusBarController.mm
+++ b/macosx/StatusBarController.mm
@@ -19,7 +19,7 @@ typedef NS_ENUM(unsigned int, statusTag) {
     STATUS_TRANSFER_SESSION_TAG = 3
 };
 
-@interface StatusBarController (Private)
+@interface StatusBarController ()
 
 - (void)resizeStatusButton;
 
@@ -236,10 +236,6 @@ typedef NS_ENUM(unsigned int, statusTag) {
     return YES;
 }
 
-@end
-
-@implementation StatusBarController (Private)
-
 - (void)resizeStatusButton
 {
     [fStatusButton sizeToFit];
diff --git a/macosx/StatusBarView.mm b/macosx/StatusBarView.mm
index 58730d2b4..992ccdba5 100644
--- a/macosx/StatusBarView.mm
+++ b/macosx/StatusBarView.mm
@@ -5,7 +5,7 @@
 #import "StatusBarView.h"
 #import "NSApplicationAdditions.h"
 
-@interface StatusBarView (Private)
+@interface StatusBarView ()
 
 - (void)reload;
 
@@ -36,10 +36,6 @@
     }
 }
 
-@end
-
-@implementation StatusBarView (Private)
-
 - (void)reload
 {
     self.needsDisplay = YES;
diff --git a/macosx/Torrent.mm b/macosx/Torrent.mm
index b408545b6..9ab64671f 100644
--- a/macosx/Torrent.mm
+++ b/macosx/Torrent.mm
@@ -19,7 +19,7 @@
 
 #define ETA_IDLE_DISPLAY_SEC (2 * 60)
 
-@interface Torrent (Private)
+@interface Torrent ()
 
 - (instancetype)initWithPath:(NSString*)path
                         hash:(NSString*)hashString
@@ -1793,10 +1793,6 @@ bool trashDataFile(char const* filename, tr_error** error)
     return location ? [NSURL fileURLWithPath:location] : nil;
 }
 
-@end
-
-@implementation Torrent (Private)
-
 - (instancetype)initWithPath:(NSString*)path
                         hash:(NSString*)hashString
                torrentStruct:(tr_torrent*)torrentStruct
diff --git a/macosx/TorrentCell.mm b/macosx/TorrentCell.mm
index 64b638cb1..f075a82dc 100644
--- a/macosx/TorrentCell.mm
+++ b/macosx/TorrentCell.mm
@@ -43,7 +43,7 @@
 
 #define MAX_PIECES (18 * 18)
 
-@interface TorrentCell (Private)
+@interface TorrentCell ()
 
 - (void)drawBar:(NSRect)barRect;
 - (void)drawRegularBar:(NSRect)barRect;
@@ -563,10 +563,6 @@
     [titleString drawInRect:cellFrame];
 }
 
-@end
-
-@implementation TorrentCell (Private)
-
 - (void)drawBar:(NSRect)barRect
 {
     BOOL const minimal = [fDefaults boolForKey:@"SmallView"];
diff --git a/macosx/TorrentTableView.mm b/macosx/TorrentTableView.mm
index 78850a8ee..6681b3a06 100644
--- a/macosx/TorrentTableView.mm
+++ b/macosx/TorrentTableView.mm
@@ -25,7 +25,7 @@
 
 #define TOGGLE_PROGRESS_SECONDS 0.175
 
-@interface TorrentTableView (Private)
+@interface TorrentTableView ()
 
 - (BOOL)pointInGroupStatusRect:(NSPoint)point;
 
@@ -960,10 +960,6 @@
     [[self.superview animator] setBoundsOrigin:scrollOrigin];
 }
 
-@end
-
-@implementation TorrentTableView (Private)
-
 - (BOOL)pointInGroupStatusRect:(NSPoint)point
 {
     NSInteger row = [self rowAtPoint:point];
diff --git a/macosx/TrackerCell.mm b/macosx/TrackerCell.mm
index 179883b95..768f49d77 100644
--- a/macosx/TrackerCell.mm
+++ b/macosx/TrackerCell.mm
@@ -18,7 +18,7 @@
 #define PADDING_BETWEEN_LINES_ON_SAME_LINE 4.0
 #define COUNT_WIDTH 40.0
 
-@interface TrackerCell (Private)
+@interface TrackerCell ()
 
 @property(nonatomic, readonly) NSImage* favIcon;
 - (void)loadTrackerIcon:(NSString*)baseAddress;
@@ -157,10 +157,6 @@ NSMutableSet* fTrackerIconLoading;
     [lastScrapeString drawInRect:lastScrapeRect];
 }
 
-@end
-
-@implementation TrackerCell (Private)
-
 - (NSImage*)favIcon
 {
     id icon = nil;
diff --git a/macosx/URLSheetWindowController.mm b/macosx/URLSheetWindowController.mm
index ccdb10e22..e0e9bfa5c 100644
--- a/macosx/URLSheetWindowController.mm
+++ b/macosx/URLSheetWindowController.mm
@@ -5,7 +5,7 @@
 #import "URLSheetWindowController.h"
 #import "Controller.h"
 
-@interface URLSheetWindowController (Private)
+@interface URLSheetWindowController ()
 
 - (void)updateOpenButtonForURL:(NSString*)string;
 
@@ -86,10 +86,6 @@ NSString* urlString = nil;
     [self updateOpenButtonForURL:fTextField.stringValue];
 }
 
-@end
-
-@implementation URLSheetWindowController (Private)
-
 - (void)updateOpenButtonForURL:(NSString*)string
 {
     BOOL enable = YES;