diff --git a/autotests/data/servicetypes/fake-kdevelopplugin.desktop b/autotests/data/servicetypes/fake-kdevelopplugin.desktop
--- a/autotests/data/servicetypes/fake-kdevelopplugin.desktop
+++ b/autotests/data/servicetypes/fake-kdevelopplugin.desktop
@@ -2,7 +2,7 @@
 
 [Desktop Entry]
 Type=ServiceType
-X-KDE-ServiceType=KDevelop/Plugin
+X-KDE-ServiceType=KDevelop/NonExistentPlugin
 X-KDE-Derived=KPluginInfo
 #Name=KDevelop Plugin
 
diff --git a/autotests/desktoptojsontest.cpp b/autotests/desktoptojsontest.cpp
--- a/autotests/desktoptojsontest.cpp
+++ b/autotests/desktoptojsontest.cpp
@@ -174,7 +174,7 @@
             "Name[fr]=Prise en charge du C++\n"
             "GenericName=Language Support\n"
             "GenericName[sl]=Podpora jeziku\n"
-            "ServiceTypes=KDevelop/Plugin\n"
+            "ServiceTypes=KDevelop/NonExistentPlugin\n"
             "X-KDE-Library=kdevcpplanguagesupport\n"
             "X-KDE-PluginInfo-Name=kdevcppsupport\n"
             "X-KDE-PluginInfo-Category=Language Support\n"
@@ -200,7 +200,7 @@
             "     \"Name\": \"C++ Support\",\n"
             "     \"Name[fi]\": \"C++-tuki\",\n"
             "     \"Name[fr]\": \"Prise en charge du C++\",\n"
-            "     \"ServiceTypes\": [ \"KDevelop/Plugin\" ]\n"
+            "     \"ServiceTypes\": [ \"KDevelop/NonExistentPlugin\" ]\n"
             " },\n"
             " \"X-KDevelop-Args\": \"CPP\",\n"
             " \"X-KDevelop-Interfaces\": \"ILanguageSupport\",\n"
@@ -226,7 +226,7 @@
             "     \"Name\": \"C++ Support\",\n"
             "     \"Name[fi]\": \"C++-tuki\",\n"
             "     \"Name[fr]\": \"Prise en charge du C++\",\n"
-            "     \"ServiceTypes\": [ \"KDevelop/Plugin\" ]\n"
+            "     \"ServiceTypes\": [ \"KDevelop/NonExistentPlugin\" ]\n"
             " },\n"
             " \"X-KDevelop-Args\": \"CPP\",\n"
             " \"X-KDevelop-Interfaces\": [\"ILanguageSupport\"],\n"
diff --git a/src/lib/plugin/desktopfileparser.cpp b/src/lib/plugin/desktopfileparser.cpp
--- a/src/lib/plugin/desktopfileparser.cpp
+++ b/src/lib/plugin/desktopfileparser.cpp
@@ -284,13 +284,18 @@
     return true;
 }
 
+static QString locateRelativeServiceType(const QString &relPath)
+{
+    return QStandardPaths::locate(QStandardPaths::GenericDataLocation,
+                                  QStringLiteral("kservicetypes5/") + relPath);
+}
+
 static QVector<CustomPropertyDefinition>* parseServiceTypesFile(const QString &inputPath)
 {
     int lineNr = 0;
     QString path = inputPath;
     if (QDir::isRelativePath(path)) {
-        path = QStandardPaths::locate(QStandardPaths::GenericDataLocation,
-                               QStringLiteral("kservicetypes5/") + inputPath);
+        path = locateRelativeServiceType(path);
         QString rcPath;
         if (path.isEmpty()) {
             rcPath = QStringLiteral(":/kservicetypes5/") + inputPath;
@@ -536,11 +541,23 @@
             break;
         }
         if (key == QByteArrayLiteral("X-KDE-ServiceTypes") || key == QByteArrayLiteral("ServiceTypes")) {
-            const auto services = deserializeList(value);
-            for(const auto &service : services) {
+            const QString dotDesktop = QStringLiteral(".desktop");
+            const QChar slashChar(QLatin1Char('/'));
+            const auto serviceList = deserializeList(value);
+
+            for(const auto &service : serviceList) {
                 // some .desktop files still use the legacy ServiceTypes= key
-                QString fileName = service.toLower().replace(QLatin1Char('/'), QLatin1Char('-'))+QStringLiteral(".desktop");
-                serviceTypeDef.addFile(fileName);
+                QString absFileName = locateRelativeServiceType(
+                        service.toLower().replace(slashChar, QLatin1Char('-'))+dotDesktop);
+                if (absFileName.isEmpty()) {
+                    absFileName = locateRelativeServiceType(
+                        service.toLower().remove(slashChar)+dotDesktop);
+                }
+                if (absFileName.isEmpty()) {
+                    qCWarning(DESKTOPPARSER) << "Unable to find service type for service" << service;
+                }
+                else
+                    serviceTypeDef.addFile(absFileName);
             }
             break;
         }