diff --git a/autotests/gravatarcachetest.h b/autotests/gravatarcachetest.h
--- a/autotests/gravatarcachetest.h
+++ b/autotests/gravatarcachetest.h
@@ -29,8 +29,10 @@
     explicit GravatarCacheTest(QObject *parent = nullptr);
     ~GravatarCacheTest();
 private Q_SLOTS:
+    void initTestCase();
     void shouldHaveDefaultValue();
     void shouldChangeCacheValue();
+    void testLookup();
 };
 
 #endif // GRAVATARCACHETEST_H
diff --git a/autotests/gravatarcachetest.cpp b/autotests/gravatarcachetest.cpp
--- a/autotests/gravatarcachetest.cpp
+++ b/autotests/gravatarcachetest.cpp
@@ -20,8 +20,12 @@
 #include "gravatarcachetest.h"
 #include "../src/misc/gravatarcache.h"
 
+#include <QPixmap>
+#include <QStandardPaths>
 #include <qtest.h>
 
+using namespace Gravatar;
+
 GravatarCacheTest::GravatarCacheTest(QObject *parent)
     : QObject(parent)
 {
@@ -31,6 +35,11 @@
 {
 }
 
+void GravatarCacheTest::initTestCase()
+{
+    QStandardPaths::setTestModeEnabled(true);
+}
+
 void GravatarCacheTest::shouldHaveDefaultValue()
 {
     Gravatar::GravatarCache gravatarCache;
@@ -50,4 +59,41 @@
     QCOMPARE(gravatarCache.maximumSize(), val);
 }
 
+void GravatarCacheTest::testLookup()
+{
+    {
+        GravatarCache cache;
+        cache.clearAllCache();
+        bool found = false;
+        const auto result = cache.loadGravatarPixmap(QStringLiteral("fa1afe1"), found);
+        QVERIFY(!found);
+        QVERIFY(result.isNull());
+    }
+
+    QPixmap px(42, 42);
+    px.fill(Qt::blue);
+
+    {
+        GravatarCache cache;
+        cache.saveGravatarPixmap(QStringLiteral("fa1afe1"), px);
+
+        // in-memory cache lookup
+        bool found = false;
+        const auto result = cache.loadGravatarPixmap(QStringLiteral("fa1afe1"), found);
+        QVERIFY(found);
+        QVERIFY(!result.isNull());
+        QCOMPARE(result.size(), QSize(42, 42));
+    }
+
+    {
+        // disk lookup
+        GravatarCache cache;
+        bool found = false;
+        const auto result = cache.loadGravatarPixmap(QStringLiteral("fa1afe1"), found);
+        QVERIFY(found);
+        QVERIFY(!result.isNull());
+        QCOMPARE(result.size(), QSize(42, 42));
+    }
+}
+
 QTEST_MAIN(GravatarCacheTest)
diff --git a/src/misc/gravatarcache.h b/src/misc/gravatarcache.h
--- a/src/misc/gravatarcache.h
+++ b/src/misc/gravatarcache.h
@@ -26,9 +26,8 @@
 
 namespace Gravatar {
 class GravatarCachePrivate;
-class GRAVATAR_EXPORT GravatarCache : public QObject
+class GRAVATAR_EXPORT GravatarCache
 {
-    Q_OBJECT
 public:
     static GravatarCache *self();
 
@@ -46,6 +45,7 @@
     void clearAllCache();
 
 private:
+    Q_DISABLE_COPY(GravatarCache)
     GravatarCachePrivate *const d;
 };
 }
diff --git a/src/misc/gravatarcache.cpp b/src/misc/gravatarcache.cpp
--- a/src/misc/gravatarcache.cpp
+++ b/src/misc/gravatarcache.cpp
@@ -33,19 +33,17 @@
 {
 public:
     GravatarCachePrivate()
-        : mMaximumSize(20)
     {
     }
 
     QCache<QString, QPixmap> mCachePixmap;
     QString mGravatarPath;
-    int mMaximumSize;
 };
 
 GravatarCache::GravatarCache()
     : d(new Gravatar::GravatarCachePrivate)
 {
-    d->mCachePixmap.setMaxCost(d->mMaximumSize);
+    d->mCachePixmap.setMaxCost(20);
     //Make sure that this folder is created. Otherwise we can't store gravatar
     d->mGravatarPath = QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation) + QLatin1String("/gravatar/");
     QDir().mkpath(d->mGravatarPath);
@@ -104,14 +102,13 @@
 
 int GravatarCache::maximumSize() const
 {
-    return d->mMaximumSize;
+    return d->mCachePixmap.maxCost();
 }
 
 void GravatarCache::setMaximumSize(int maximumSize)
 {
-    if (d->mMaximumSize != maximumSize) {
-        d->mMaximumSize = maximumSize;
-        d->mCachePixmap.setMaxCost(d->mMaximumSize);
+    if (d->mCachePixmap.maxCost() != maximumSize) {
+        d->mCachePixmap.setMaxCost(maximumSize);
     }
 }