diff --git a/src/libs/qmljs/qmljscheck.cpp b/src/libs/qmljs/qmljscheck.cpp
index 403355426fd..9db241266a0 100644
--- a/src/libs/qmljs/qmljscheck.cpp
+++ b/src/libs/qmljs/qmljscheck.cpp
@@ -1390,12 +1390,20 @@ void Check::warnAboutUnnecessarySuppressions()
 
 bool Check::isQtQuick2() const
 {
-    foreach (const Import &import, _imports->all()) {
-        if (import.info.name() == QLatin1String("QtQuick")
-                && import.info.version().majorVersion() == 2)
-            return true;
+    if (_doc->language() == Dialect::Qml) {
+        foreach (const Import &import, _imports->all()) {
+            if (import.info.name() == QLatin1String("QtQuick")
+                    && import.info.version().majorVersion() == 2)
+                return true;
+        }
+        return false;
     }
-    return false;
+    return _doc->language() == Dialect::QmlQtQuick2 || _doc->language() == Dialect::QmlQtQuick2Ui;
+}
+
+bool Check::isQtQuick2Ui() const
+{
+    return _doc->language() == Dialect::QmlQtQuick2Ui;
 }
 
 bool Check::visit(NewExpression *ast)
diff --git a/src/libs/qmljs/qmljscheck.h b/src/libs/qmljs/qmljscheck.h
index a4e37981525..b5247856fea 100644
--- a/src/libs/qmljs/qmljscheck.h
+++ b/src/libs/qmljs/qmljscheck.h
@@ -118,6 +118,7 @@ private:
     void warnAboutUnnecessarySuppressions();
 
     bool isQtQuick2() const;
+    bool isQtQuick2Ui() const;
 
     AST::Node *parent(int distance = 0);
 
diff --git a/src/libs/qmljs/qmljsdialect.cpp b/src/libs/qmljs/qmljsdialect.cpp
index 2641f6bf7c6..4330db263de 100644
--- a/src/libs/qmljs/qmljsdialect.cpp
+++ b/src/libs/qmljs/qmljsdialect.cpp
@@ -38,6 +38,7 @@ bool Dialect::isQmlLikeLanguage() const
     case Dialect::Qml:
     case Dialect::QmlQtQuick1:
     case Dialect::QmlQtQuick2:
+    case Dialect::QmlQtQuick2Ui:
     case Dialect::QmlQbs:
     case Dialect::QmlProject:
     case Dialect::QmlTypeInfo:
@@ -56,6 +57,7 @@ bool Dialect::isFullySupportedLanguage() const
     case Dialect::Qml:
     case Dialect::QmlQtQuick1:
     case Dialect::QmlQtQuick2:
+    case Dialect::QmlQtQuick2Ui:
         return true;
     case Dialect::NoLanguage:
     case Dialect::AnyLanguage:
@@ -73,6 +75,7 @@ bool Dialect::isQmlLikeOrJsLanguage() const
     case Dialect::Qml:
     case Dialect::QmlQtQuick1:
     case Dialect::QmlQtQuick2:
+    case Dialect::QmlQtQuick2Ui:
     case Dialect::QmlQbs:
     case Dialect::QmlProject:
     case Dialect::QmlTypeInfo:
@@ -97,6 +100,8 @@ QString Dialect::toString() const
         return QLatin1String("QmlQtQuick1");
     case Dialect::QmlQtQuick2:
         return QLatin1String("QmlQtQuick2");
+    case Dialect::QmlQtQuick2Ui:
+        return QLatin1String("QmlQtQuick2Ui");
     case Dialect::NoLanguage:
         return QLatin1String("NoLanguage");
     case Dialect::AnyLanguage:
@@ -178,6 +183,9 @@ bool Dialect::restrictLanguage(const Dialect &l2)
     }
     if (i2 && !i1)
         return true;
+    qDebug() << toString() << "restrictTo" << l2.toString() << "failed";
+    qDebug() << ll1 << ll2;
+    qDebug() << i1 << i2;
     QList<Dialect> qmlLangs = Dialect(Qml).companionLanguages();
     if (qmlLangs.contains(*this) && qmlLangs.contains(l2))
         *this = Dialect::Qml;
@@ -199,16 +207,22 @@ QList<Dialect> Dialect::companionLanguages() const
         langs << Dialect::JavaScript;
         break;
     case Dialect::Qml:
-        langs << Dialect::QmlQtQuick1 << Dialect::QmlQtQuick2 << Dialect::JavaScript;
+        langs << Dialect::QmlQtQuick1 << Dialect::QmlQtQuick2 << Dialect::QmlQtQuick2Ui
+              << Dialect::JavaScript;
         break;
     case Dialect::QmlQtQuick1:
-    case Dialect::QmlQtQuick2:
         langs << Dialect::Qml << Dialect::JavaScript;
         break;
+    case Dialect::QmlQtQuick2:
+    case Dialect::QmlQtQuick2Ui:
+        langs.clear();
+        langs << Dialect::QmlQtQuick2 << Dialect::QmlQtQuick2Ui << Dialect::Qml
+              << Dialect::JavaScript;
+        break;
     case Dialect::AnyLanguage:
         langs << Dialect::JavaScript << Dialect::Json << Dialect::QmlProject << Dialect:: QmlQbs
               << Dialect::QmlTypeInfo << Dialect::QmlQtQuick1 << Dialect::QmlQtQuick2
-              << Dialect::Qml;
+              << Dialect::QmlQtQuick2Ui << Dialect::Qml;
         break;
     case Dialect::NoLanguage:
         return QList<Dialect>(); // return at least itself?
diff --git a/src/libs/qmljs/qmljsdialect.h b/src/libs/qmljs/qmljsdialect.h
index 3ee6f26c125..accb00956af 100644
--- a/src/libs/qmljs/qmljsdialect.h
+++ b/src/libs/qmljs/qmljsdialect.h
@@ -51,7 +51,8 @@ public:
         QmlQbs = 6,
         QmlProject = 7,
         QmlTypeInfo = 8,
-        AnyLanguage = 9,
+        QmlQtQuick2Ui = 9,
+        AnyLanguage = 10,
     };
     Dialect(Enum dialect = NoLanguage)
         : m_dialect(dialect)
diff --git a/src/libs/qmljs/qmljsmodelmanagerinterface.cpp b/src/libs/qmljs/qmljsmodelmanagerinterface.cpp
index be664ba56d9..f8413ad3ec2 100644
--- a/src/libs/qmljs/qmljsmodelmanagerinterface.cpp
+++ b/src/libs/qmljs/qmljsmodelmanagerinterface.cpp
@@ -78,6 +78,8 @@ QMLJS_EXPORT Q_LOGGING_CATEGORY(qmljsLog, "qtc.qmljs.common")
 
 static ModelManagerInterface *g_instance = 0;
 
+const char qtQuickUISuffix[] = "ui.qml";
+
 static QStringList environmentImportPaths()
 {
     QStringList paths;
@@ -148,6 +150,7 @@ static QHash<QString, Dialect> defaultLanguageMapping()
     res[QLatin1String("qmlproject")] = Dialect::QmlProject;
     res[QLatin1String("json")] = Dialect::Json;
     res[QLatin1String("qbs")] = Dialect::QmlQbs;
+    res[QLatin1String(qtQuickUISuffix)] = Dialect::QmlQtQuick2Ui;
     return res;
 }
 
@@ -159,7 +162,16 @@ Dialect ModelManagerInterface::guessLanguageOfFile(const QString &fileName)
     else
         lMapping = defaultLanguageMapping();
     const QFileInfo info(fileName);
-    const QString fileSuffix = info.suffix();
+    QString fileSuffix = info.suffix();
+
+    /*
+     * I was reluctant to use complete suffix in all cases, because it is a huge
+     * change in behaivour. But in case of .qml this should be safe.
+     */
+
+    if (fileSuffix == QLatin1String("qml"))
+        fileSuffix = info.completeSuffix();
+
     return lMapping.value(fileSuffix, Dialect::NoLanguage);
 }
 
@@ -856,6 +868,8 @@ void ModelManagerInterface::parseLoop(QSet<QString> &scannedPaths,
         if (language == Dialect::Qml
                 && (mainLanguage == Dialect::QmlQtQuick1 || mainLanguage == Dialect::QmlQtQuick2))
             language = mainLanguage;
+        if (language == Dialect::Qml && mainLanguage == Dialect::QmlQtQuick2Ui)
+            language = Dialect::QmlQtQuick2;
         QString contents;
         int documentRevision = 0;
 
@@ -1314,7 +1328,8 @@ ViewerContext ModelManagerInterface::completeVContext(const ViewerContext &vCtx,
             && ((vCtx.language == Dialect::AnyLanguage && doc->language() != Dialect::NoLanguage)
                 || (vCtx.language == Dialect::Qml
                     && (doc->language() == Dialect::QmlQtQuick1
-                        || doc->language() == Dialect::QmlQtQuick2))))
+                        || doc->language() == Dialect::QmlQtQuick2
+                        || doc->language() == Dialect::QmlQtQuick2Ui))))
         res.language = doc->language();
     ProjectInfo info;
     if (!doc.isNull())
@@ -1344,8 +1359,9 @@ ViewerContext ModelManagerInterface::completeVContext(const ViewerContext &vCtx,
             res.maybeAddPath(info.qtImportsPath);
             // fallthrough
         case Dialect::QmlQtQuick2:
+        case Dialect::QmlQtQuick2Ui:
         {
-            if (res.language == Dialect::QmlQtQuick2)
+            if (res.language == Dialect::QmlQtQuick2 || res.language == Dialect::QmlQtQuick2Ui)
                 res.maybeAddPath(info.qtQmlPath);
             QList<ProjectInfo> allProjects;
             {
@@ -1382,13 +1398,14 @@ ViewerContext ModelManagerInterface::completeVContext(const ViewerContext &vCtx,
         foreach (const QString &path, defaultVCtx.paths)
             res.maybeAddPath(path);
         if (res.language == Dialect::AnyLanguage || res.language == Dialect::Qml
-                || res.language == Dialect::QmlQtQuick2)
+                || res.language == Dialect::QmlQtQuick2 || res.language == Dialect::QmlQtQuick2Ui)
             res.maybeAddPath(info.qtImportsPath);
         if (res.language == Dialect::AnyLanguage || res.language == Dialect::Qml
                 || res.language == Dialect::QmlQtQuick1)
             res.maybeAddPath(info.qtQmlPath);
         if (res.language == Dialect::AnyLanguage || res.language == Dialect::Qml
-                || res.language == Dialect::QmlQtQuick1 || res.language == Dialect::QmlQtQuick2) {
+                || res.language == Dialect::QmlQtQuick1 || res.language == Dialect::QmlQtQuick2
+                || res.language == Dialect::QmlQtQuick2Ui) {
             foreach (const QString &path, environmentImportPaths())
                 res.maybeAddPath(path);
         }
@@ -1406,7 +1423,8 @@ ViewerContext ModelManagerInterface::defaultVContext(Dialect language,
         if (language == Dialect::AnyLanguage && doc->language() != Dialect::NoLanguage)
             language = doc->language();
         else if (language == Dialect::Qml &&
-                 (doc->language() == Dialect::QmlQtQuick1 || doc->language() == Dialect::QmlQtQuick2))
+                 (doc->language() == Dialect::QmlQtQuick1 || doc->language() == Dialect::QmlQtQuick2
+                  || doc->language() == Dialect::QmlQtQuick2Ui))
             language = doc->language();
     }
     ViewerContext defaultCtx;
diff --git a/src/libs/qmljs/qmljsviewercontext.cpp b/src/libs/qmljs/qmljsviewercontext.cpp
index 14482f1158e..15bace4000d 100644
--- a/src/libs/qmljs/qmljsviewercontext.cpp
+++ b/src/libs/qmljs/qmljsviewercontext.cpp
@@ -71,7 +71,9 @@ bool ViewerContext::languageIsCompatible(Dialect l) const
     case Dialect::QmlQtQuick1:
         return l == Dialect::Qml || l == Dialect::QmlQtQuick1 || l == Dialect::JavaScript;
     case Dialect::QmlQtQuick2:
-        return l == Dialect::Qml || l == Dialect::QmlQtQuick2 || l == Dialect::JavaScript;
+    case Dialect::QmlQtQuick2Ui:
+        return l == Dialect::Qml || l == Dialect::QmlQtQuick2 || l == Dialect::QmlQtQuick2Ui
+            || l == Dialect::JavaScript;
     case Dialect::AnyLanguage:
         return true;
     case Dialect::NoLanguage:
diff --git a/src/plugins/qmldesigner/qmldesignerplugin.cpp b/src/plugins/qmldesigner/qmldesignerplugin.cpp
index e07c6d4ae7e..c4ce16e9c45 100644
--- a/src/plugins/qmldesigner/qmldesignerplugin.cpp
+++ b/src/plugins/qmldesigner/qmldesignerplugin.cpp
@@ -366,6 +366,7 @@ static bool checkIfEditorIsQtQuick(Core::IEditor *editor)
         if (!document.isNull())
             return document->language() == QmlJS::Dialect::QmlQtQuick1
                     || document->language() == QmlJS::Dialect::QmlQtQuick2
+                    || document->language() == QmlJS::Dialect::QmlQtQuick2Ui
                     || document->language() == QmlJS::Dialect::Qml;
     }
 
diff --git a/src/plugins/qmljstools/QmlJSTools.mimetypes.xml b/src/plugins/qmljstools/QmlJSTools.mimetypes.xml
index a1bdef531ef..048a192e9d9 100644
--- a/src/plugins/qmljstools/QmlJSTools.mimetypes.xml
+++ b/src/plugins/qmljstools/QmlJSTools.mimetypes.xml
@@ -4,7 +4,7 @@
         <alias type="text/x-qml"/>
         <sub-class-of type="text/plain"/>
         <comment>QML file</comment>
-        <glob pattern="*.qml"/>
+        <glob weight="50" pattern="*.qml"/>
     </mime-type>
     <mime-type type="application/x-qt.qbs+qml">
         <alias type="text/x-qt.qbs+qml"/>
@@ -12,6 +12,12 @@
         <comment>Qt Build Suite file</comment>
         <glob pattern="*.qbs"/>
     </mime-type>
+    <mime-type type="application/x-qt.ui+qml">
+        <alias type="text/x-qt.ui+qml"/>
+        <sub-class-of type="application/x-qml"/>
+        <comment>QtQuick Designer ui file</comment>
+        <glob weight="100" pattern="*.ui.qml"/>
+    </mime-type>
     <mime-type type="application/x-qmlproject">
         <alias type="text/x-qmlproject"/>
         <sub-class-of type="application/x-qml"/>
diff --git a/src/plugins/qmljstools/qmljsbundleprovider.cpp b/src/plugins/qmljstools/qmljsbundleprovider.cpp
index 5b125591f16..a75bbdefb11 100644
--- a/src/plugins/qmljstools/qmljsbundleprovider.cpp
+++ b/src/plugins/qmljstools/qmljsbundleprovider.cpp
@@ -127,6 +127,7 @@ void BasicBundleProvider::mergeBundlesForKit(ProjectExplorer::Kit *kit
         QmlBundle b2(defaultQt5QtQuick2Bundle());
         bundles.mergeBundleForLanguage(Dialect::Qml, b2);
         bundles.mergeBundleForLanguage(Dialect::QmlQtQuick2, b2);
+        bundles.mergeBundleForLanguage(Dialect::QmlQtQuick2Ui, b2);
         return;
     }
     QString qtImportsPath = qtVersion->qmakeProperty("QT_INSTALL_IMPORTS");
@@ -181,6 +182,7 @@ void BasicBundleProvider::mergeBundlesForKit(ProjectExplorer::Kit *kit
         qtQuick2Bundle.replaceVars(myReplacements);
         bundles.mergeBundleForLanguage(Dialect::Qml, qtQuick2Bundle);
         bundles.mergeBundleForLanguage(Dialect::QmlQtQuick2, qtQuick2Bundle);
+        bundles.mergeBundleForLanguage(Dialect::QmlQtQuick2Ui, qtQuick2Bundle);
     }
 }
 
diff --git a/src/plugins/qmljstools/qmljsmodelmanager.cpp b/src/plugins/qmljstools/qmljsmodelmanager.cpp
index 31b00169c19..c64fb7a3f65 100644
--- a/src/plugins/qmljstools/qmljsmodelmanager.cpp
+++ b/src/plugins/qmljstools/qmljsmodelmanager.cpp
@@ -189,6 +189,9 @@ QHash<QString,QmlJS::Dialect> ModelManager::languageForSuffix() const
         MimeType qmlProjectSourceTy = MimeDatabase::findByType(QLatin1String(Constants::QMLPROJECT_MIMETYPE));
         foreach (const QString &suffix, qmlProjectSourceTy.suffixes())
             res[suffix] = Dialect::QmlProject;
+        MimeType qmlUiSourceTy = MimeDatabase::findByType(QLatin1String(Constants::QMLUI_MIMETYPE));
+        foreach (const QString &suffix, qmlUiSourceTy.suffixes())
+            res[suffix] = Dialect::QmlQtQuick2Ui;
         MimeType jsonSourceTy = MimeDatabase::findByType(QLatin1String(Constants::JSON_MIMETYPE));
         foreach (const QString &suffix, jsonSourceTy.suffixes())
             res[suffix] = Dialect::Json;
diff --git a/src/plugins/qmljstools/qmljstoolsconstants.h b/src/plugins/qmljstools/qmljstoolsconstants.h
index b5de5aabb97..bc23aeddc00 100644
--- a/src/plugins/qmljstools/qmljstoolsconstants.h
+++ b/src/plugins/qmljstools/qmljstoolsconstants.h
@@ -39,6 +39,7 @@ const char QML_MIMETYPE[] = "application/x-qml"; // separate def also in project
 const char QBS_MIMETYPE[] = "application/x-qt.qbs+qml";
 const char QMLPROJECT_MIMETYPE[] = "application/x-qmlproject";
 const char QMLTYPES_MIMETYPE[] = "application/x-qt.meta-info+qml";
+const char QMLUI_MIMETYPE[] = "application/x-qt.ui+qml";
 const char JS_MIMETYPE[] = "application/javascript";
 const char JSON_MIMETYPE[] = "application/json";