diff --git a/autotests/propertyinfotest.h b/autotests/propertyinfotest.h
--- a/autotests/propertyinfotest.h
+++ b/autotests/propertyinfotest.h
@@ -31,6 +31,7 @@
 private Q_SLOTS:
     void testNameIdMapping();
     void testFormatAsDisplayString();
+    void testVariantMapConversion();
 };
 
 }
diff --git a/autotests/propertyinfotest.cpp b/autotests/propertyinfotest.cpp
--- a/autotests/propertyinfotest.cpp
+++ b/autotests/propertyinfotest.cpp
@@ -93,4 +93,17 @@
     QCOMPARE(framerate.formatAsDisplayString(QVariant(23)), QStringLiteral("23 fps"));
 }
 
+void PropertyInfoTest::testVariantMapConversion()
+{
+    PropertyMap propMap;
+    propMap.insertMulti(Property::Title, QStringLiteral("Title"));
+    propMap.insertMulti(Property::Artist, QStringLiteral("Artist1"));
+    propMap.insertMulti(Property::Artist, QStringLiteral("Artist2"));
+    propMap.insertMulti(Property::Lyricist, QStringList({QStringLiteral("Lyricist1"), QStringLiteral("Lyricist2")}));
+    propMap.insertMulti(Property::ReleaseYear, 2019);
+
+    PropertyMap propMap2 = toPropertyMap(toVariantMap(propMap));
+    QCOMPARE(propMap, propMap2);
+}
+
 QTEST_GUILESS_MAIN(PropertyInfoTest)
diff --git a/src/properties.h b/src/properties.h
--- a/src/properties.h
+++ b/src/properties.h
@@ -362,8 +362,19 @@
 
 } // namespace Property
 
+/**
+ * PropertyMap is a map which stores the results as
+ * <Property::Property, QVariant> pairs
+ * obtained from the extractors.
+ */
 typedef QMap<Property::Property, QVariant> PropertyMap;
 
+/**
+ * Converts a PropertyMap to a QVariantMap.
+ * The Property::Property enum is converted to its integer
+ * representation and stored as a string as key in the
+ * QVariantMap.
+ */
 inline QVariantMap toVariantMap(const PropertyMap& propMap) {
     QVariantMap varMap;
     PropertyMap::const_iterator it = propMap.constBegin();
@@ -375,6 +386,11 @@
     return varMap;
 }
 
+/**
+ * Converts a QVariantMap to a PropertyMap. The keys of
+ * the QVariantMap must contain the integer representation
+ * of the Property::Property enum as a string.
+ */
 inline PropertyMap toPropertyMap(const QVariantMap& varMap) {
     PropertyMap propMap;
     QVariantMap::const_iterator it = varMap.constBegin();