diff --git a/tests/auto/gui/image/qpixmapcache/tst_qpixmapcache.cpp b/tests/auto/gui/image/qpixmapcache/tst_qpixmapcache.cpp
index 227e7b60af1..b161f9f9063 100644
--- a/tests/auto/gui/image/qpixmapcache/tst_qpixmapcache.cpp
+++ b/tests/auto/gui/image/qpixmapcache/tst_qpixmapcache.cpp
@@ -50,6 +50,7 @@ private slots:
     void setCacheLimit();
     void find();
     void insert();
+    void failedInsertReturnsInvalidKey();
     void replace();
     void remove();
     void clear();
@@ -318,6 +319,7 @@ void tst_QPixmapCache::insert()
     for (int i = 0; i < numberOfKeys; ++i) {
         QPixmap p3(10,10);
         keys.append(QPixmapCache::insert(p3));
+        QVERIFY(keys.back().isValid());
     }
 
     num = 0;
@@ -331,6 +333,32 @@ void tst_QPixmapCache::insert()
     QVERIFY(num <= estimatedNum);
 }
 
+void tst_QPixmapCache::failedInsertReturnsInvalidKey()
+{
+    //
+    // GIVEN: a pixmap whose memory footprint exceeds the cache's limit:
+    //
+    QPixmapCache::setCacheLimit(20);
+
+    QPixmap pm(256, 256);
+    pm.fill(Qt::transparent);
+    QVERIFY(pm.width() * pm.height() * pm.depth() / 8
+            > QPixmapCache::cacheLimit() * 1024);
+
+    //
+    // WHEN: trying to add this pixmap to the cache
+    //
+    const auto success = QPixmapCache::insert(QStringLiteral("foo"), pm); // QString API
+    { QPixmap r; QVERIFY(!QPixmapCache::find(QStringLiteral("foo"), &r)); }
+    const auto key = QPixmapCache::insert(pm);               // "int" API
+
+    //
+    // THEN: failure is reported to the user
+    //
+    QVERIFY(!key.isValid()); // "int" API
+    QVERIFY(!success);       // QString API
+}
+
 void tst_QPixmapCache::replace()
 {
     //The int part of the API