diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index e2d867e623..821e10de52 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -122,7 +122,9 @@ void QCocoaScreen::updateGeometry()
     m_physicalSize = QSizeF(size.width, size.height);
     m_logicalDpi.first = 72;
     m_logicalDpi.second = 72;
-    float refresh = CGDisplayModeGetRefreshRate(CGDisplayCopyDisplayMode(dpy));
+    CGDisplayModeRef displayMode = CGDisplayCopyDisplayMode(dpy);
+    float refresh = CGDisplayModeGetRefreshRate(displayMode);
+    CGDisplayModeRelease(displayMode);
     if (refresh > 0)
         m_refreshRate = refresh;
 
diff --git a/src/plugins/platforms/cocoa/qcocoamenu.mm b/src/plugins/platforms/cocoa/qcocoamenu.mm
index 732851ecf7..bde9ded14f 100644
--- a/src/plugins/platforms/cocoa/qcocoamenu.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenu.mm
@@ -323,7 +323,8 @@ void QCocoaMenu::showPopup(const QWindow *parentWindow, QPoint pos, const QPlatf
         // typical use-case for a choice list, or non-editable combobox. We can't
         // re-use the popUpContextMenu:withEvent:forView: logic below since it won't
         // respect the menu's minimum width.
-        NSPopUpButtonCell *popupCell = [[NSPopUpButtonCell alloc] initTextCell:@"" pullsDown:NO];
+        NSPopUpButtonCell *popupCell = [[[NSPopUpButtonCell alloc] initTextCell:@"" pullsDown:NO]
+                                                                   autorelease];
         [popupCell setAltersStateOfSelectedItem:NO];
         [popupCell setTransparent:YES];
         [popupCell setMenu:m_nativeMenu];
@@ -350,7 +351,6 @@ void QCocoaMenu::showPopup(const QWindow *parentWindow, QPoint pos, const QPlatf
                                     eventNumber:0
                                     clickCount:1
                                     pressure:1.0];
-        NSSize size = m_nativeMenu.size;
         [NSMenu popUpContextMenu:m_nativeMenu withEvent:menuEvent forView:view];
     }
 
diff --git a/src/plugins/platforms/cocoa/qcocoasystemsettings.mm b/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
index e613dbbd1b..af817bd4c5 100644
--- a/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
+++ b/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
@@ -176,7 +176,7 @@ QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes()
     QHash<QPlatformTheme::Palette, QPalette*> palettes;
     QColor qc;
     for (int i = 0; mac_widget_colors[i].paletteRole != QPlatformTheme::NPalettes; i++) {
-        QPalette pal = *qt_mac_createSystemPalette();
+        QPalette &pal = *qt_mac_createSystemPalette();
         if (mac_widget_colors[i].active != 0) {
             qc = qt_mac_colorForThemeTextColor(mac_widget_colors[i].active);
             pal.setColor(QPalette::Active, QPalette::Text, qc);
@@ -223,7 +223,7 @@ QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes()
             pal.setBrush(QPalette::Disabled, QPalette::Base,
                          pal.brush(QPalette::Active, QPalette::Base));
         }
-        palettes.insert(mac_widget_colors[i].paletteRole, new QPalette(pal));
+        palettes.insert(mac_widget_colors[i].paletteRole, &pal);
     }
     return palettes;
 }
diff --git a/src/widgets/styles/qmacstyle_mac.mm b/src/widgets/styles/qmacstyle_mac.mm
index 04fea3ec47..c9cc56b101 100644
--- a/src/widgets/styles/qmacstyle_mac.mm
+++ b/src/widgets/styles/qmacstyle_mac.mm
@@ -1785,6 +1785,7 @@ QMacStyle::~QMacStyle()
 
         NotificationReceiver *receiver = static_cast<NotificationReceiver *>(d->receiver);
         [[NSNotificationCenter defaultCenter] removeObserver:receiver];
+        [receiver release];
     }
 #endif