diff --git a/src/Draw/Draw_Window_1.mm b/src/Draw/Draw_Window_1.mm
index e419a5a37e..222d72881a 100644
--- a/src/Draw/Draw_Window_1.mm
+++ b/src/Draw/Draw_Window_1.mm
@@ -48,7 +48,7 @@
 
 - (void )drawRect: (NSRect )theRect
 {
-
+  (void )theRect;
   NSRect aBounds = NSMakeRect (0.0, 0.0, myImage.size.width, myImage.size.height);
 
   [myImage drawInRect: aBounds
@@ -511,7 +511,8 @@ void Draw_Window::SetColor (const Standard_Integer& theColor)
 //=======================================================================
 void Draw_Window::SetMode (const Standard_Integer& theMode)
 {
-  //
+  // unsupported
+  (void )theMode;
 }
 
 //=======================================================================
@@ -539,8 +540,11 @@ Standard_Boolean Draw_Window::Save (Standard_CString theFileName) const
   NSBitmapImageFileType aFileType = (NSBitmapImageFileType )[[aFileTypeDict valueForKey: aFileExtension] intValue];
   NSBitmapImageRep* anImageRep = [NSBitmapImageRep imageRepWithData: [myImageBuffer TIFFRepresentation]];
 
+  NSDictionary* anImgProps = [NSDictionary dictionaryWithObject: [NSNumber numberWithFloat: 0.8]
+                                                         forKey: NSImageCompressionFactor];
+
   NSData* aData = [anImageRep representationUsingType: aFileType 
-                                           properties: nil];
+                                           properties: anImgProps];
 
   Standard_Boolean isSuccess = [aData writeToFile: aFileName
                                        atomically: NO];
diff --git a/src/OpenGl/OpenGl_Window_1.mm b/src/OpenGl/OpenGl_Window_1.mm
index 8fa77eb145..c2b02b2b7d 100644
--- a/src/OpenGl/OpenGl_Window_1.mm
+++ b/src/OpenGl/OpenGl_Window_1.mm
@@ -66,6 +66,7 @@ OpenGl_Window::OpenGl_Window (const Handle(OpenGl_GraphicDriver)& theDriver,
 #endif
   mySwapInterval (theCaps->swapInterval)
 {
+  (void )theDriver;
   myPlatformWindow->Size (myWidth, myHeight);
 
 #if defined(__APPLE__)
diff --git a/src/ViewerTest/ViewerTest_ViewerCommands_1.mm b/src/ViewerTest/ViewerTest_ViewerCommands_1.mm
index a05daa99b8..e29bd354e8 100644
--- a/src/ViewerTest/ViewerTest_ViewerCommands_1.mm
+++ b/src/ViewerTest/ViewerTest_ViewerCommands_1.mm
@@ -105,6 +105,7 @@ TCollection_AsciiString FindViewId (const NSWindow* theWindow)
 
 - (void )windowWillClose: (NSNotification* )theNotification
 {
+  (void )theNotification;
   TCollection_AsciiString aViewId = "";
   if (ViewerTest_myViews.IsBound2 (ViewerTest::CurrentView()))
   {
@@ -196,6 +197,7 @@ static void getMouseCoords (NSView*           theView,
 // =======================================================================
 - (void )drawRect: (NSRect )theDirtyRect
 {
+  (void )theDirtyRect;
   VT_ProcessExpose();
 }
 
@@ -269,6 +271,7 @@ static void getMouseCoords (NSView*           theView,
 // =======================================================================
 - (void )rightMouseUp: (NSEvent* )theEvent
 {
+  (void )theEvent;
   VT_ProcessButton3Release();
 }