diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibility.mm b/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
index 585518628db..0f5c638f7c6 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
@@ -389,6 +389,8 @@ id getValueAttribute(QAccessibleInterface *interface)
     }
 
     if (interface->state().checkable) {
+        if (interface->state().checkStateMixed)
+            return @(2);
         return interface->state().checked ? @(1) : @(0);
     }
 
diff --git a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac.cpp b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac.cpp
index 404129e284d..a766e1e374a 100644
--- a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac.cpp
+++ b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac.cpp
@@ -143,7 +143,7 @@ void tst_QAccessibilityMac::checkBoxTest()
     QVERIFY(QTest::qWaitForWindowExposed(m_window));
     QCoreApplication::processEvents();
 
-    QVERIFY(testCheckBox());
+    QVERIFY(testCheckBox(cb));
 }
 
 QTEST_MAIN(tst_QAccessibilityMac)
diff --git a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.h b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.h
index 75b2d39a001..58ea2d02b0b 100644
--- a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.h
+++ b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.h
@@ -28,6 +28,7 @@
 #include <QtCore/QString>
 #include <QtCore/QPair>
 #include <QtWidgets/QWidget>
+#include <QtWidgets/QCheckBox>
 
 #pragma once // Yeah, it's deprecated in general, but it's standard practice for Mac OS X.
 
@@ -37,4 +38,4 @@ bool testLineEdit();
 bool testHierarchy(QWidget *w);
 bool singleWidget();
 bool notifications(QWidget *w);
-bool testCheckBox();
+bool testCheckBox(QCheckBox *ckBox);
diff --git a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm
index a40ebaa2526..b7c3c2643b7 100644
--- a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm
+++ b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm
@@ -565,7 +565,7 @@ bool notifications(QWidget *w)
     return true;
 }
 
-bool testCheckBox()
+bool testCheckBox(QCheckBox *ckBox)
 {
     TestAXObject *appObject = [TestAXObject getApplicationAXObject];
     EXPECT(appObject);
@@ -596,5 +596,8 @@ bool testCheckBox()
     [cb performAction:kAXPressAction];
     EXPECT([cb valueNumber] == 0);
 
+    ckBox->setCheckState(Qt::PartiallyChecked);
+    EXPECT([cb valueNumber] == 2);
+
     return true;
 }