diff --git a/src/plugins/platforms/cocoa/qcocoadrag.mm b/src/plugins/platforms/cocoa/qcocoadrag.mm
index a8404889e97..3a9f5a87941 100644
--- a/src/plugins/platforms/cocoa/qcocoadrag.mm
+++ b/src/plugins/platforms/cocoa/qcocoadrag.mm
@@ -9,7 +9,6 @@
 #include "qcocoahelpers.h"
 #include <QtGui/private/qcoregraphics_p.h>
 #include <QtGui/qutimimeconverter.h>
-#include <QtCore/qsysinfo.h>
 #include <QtCore/private/qcore_mac_p.h>
 
 #include <vector>
@@ -137,11 +136,6 @@ bool QCocoaDrag::maybeDragMultipleItems()
     Q_ASSERT(m_drag && m_drag->mimeData());
     Q_ASSERT(m_executed_drop_action == Qt::IgnoreAction);
 
-    if (QOperatingSystemVersion::current() < QOperatingSystemVersion::MacOSMojave) {
-        // -dragImage: stopped working in 10.14 first.
-        return false;
-    }
-
     const QMacAutoReleasePool pool;
 
     NSView *view = m_lastView ? m_lastView : m_lastEvent.window.contentView;
diff --git a/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm b/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
index 044a2826866..41170b74eaa 100644
--- a/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
+++ b/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
@@ -14,8 +14,6 @@
 #include <QtCore/qstringlist.h>
 #include <QtCore/qvarlengtharray.h>
 #include <QtCore/qabstracteventdispatcher.h>
-#include <QtCore/qsysinfo.h>
-#include <QtCore/qoperatingsystemversion.h>
 #include <QtCore/qdir.h>
 #include <QtCore/qregularexpression.h>
 #include <QtCore/qpointer.h>
diff --git a/src/plugins/platforms/cocoa/qcocoatheme.mm b/src/plugins/platforms/cocoa/qcocoatheme.mm
index d9135c76c83..f3f3e05b502 100644
--- a/src/plugins/platforms/cocoa/qcocoatheme.mm
+++ b/src/plugins/platforms/cocoa/qcocoatheme.mm
@@ -5,7 +5,6 @@
 
 #include "qcocoatheme.h"
 
-#include <QtCore/QOperatingSystemVersion>
 #include <QtCore/QVariant>
 
 #include "qcocoasystemtrayicon.h"
@@ -214,12 +213,10 @@ const char *QCocoaTheme::name = "cocoa";
 QCocoaTheme::QCocoaTheme()
     : m_systemPalette(nullptr)
 {
-    if (QOperatingSystemVersion::current() >= QOperatingSystemVersion::MacOSMojave) {
-        m_appearanceObserver = QMacKeyValueObserver(NSApp, @"effectiveAppearance", [this] {
-            NSAppearance.currentAppearance = NSApp.effectiveAppearance;
-            handleSystemThemeChange();
-        });
-    }
+    m_appearanceObserver = QMacKeyValueObserver(NSApp, @"effectiveAppearance", [this] {
+        NSAppearance.currentAppearance = NSApp.effectiveAppearance;
+        handleSystemThemeChange();
+    });
 
     m_systemColorObserver = QMacNotificationObserver(nil,
         NSSystemColorsDidChangeNotification, [this] {
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index c63a8e28790..eb998b04099 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -21,7 +21,6 @@
 #include <QtCore/QDebug>
 #include <QtCore/QPointer>
 #include <QtCore/QSet>
-#include <QtCore/qsysinfo.h>
 #include <QtCore/private/qcore_mac_p.h>
 #include <QtGui/QAccessible>
 #include <QtGui/QImage>
diff --git a/src/plugins/platforms/cocoa/qnsview_gestures.mm b/src/plugins/platforms/cocoa/qnsview_gestures.mm
index 7c64e3356f4..9c5ead072bd 100644
--- a/src/plugins/platforms/cocoa/qnsview_gestures.mm
+++ b/src/plugins/platforms/cocoa/qnsview_gestures.mm
@@ -11,9 +11,6 @@ Q_LOGGING_CATEGORY(lcQpaGestures, "qt.qpa.input.gestures")
 
 - (bool)handleGestureAsBeginEnd:(NSEvent *)event
 {
-    if (QOperatingSystemVersion::current() < QOperatingSystemVersion::OSXElCapitan)
-        return false;
-
     if ([event phase] == NSEventPhaseBegan) {
         [self beginGestureWithEvent:event];
         return true;
diff --git a/src/plugins/platforms/cocoa/qnswindow.mm b/src/plugins/platforms/cocoa/qnswindow.mm
index 78ad1a7e998..f536045fec8 100644
--- a/src/plugins/platforms/cocoa/qnswindow.mm
+++ b/src/plugins/platforms/cocoa/qnswindow.mm
@@ -12,7 +12,6 @@
 #include "qcocoaintegration.h"
 
 #include <qpa/qwindowsysteminterface.h>
-#include <qoperatingsystemversion.h>
 
 Q_LOGGING_CATEGORY(lcQpaEvents, "qt.qpa.events");