diff --git a/src/plugins/projectexplorer/kitinformation.cpp b/src/plugins/projectexplorer/kitinformation.cpp
index 9d14a93638d..729e1594f55 100644
--- a/src/plugins/projectexplorer/kitinformation.cpp
+++ b/src/plugins/projectexplorer/kitinformation.cpp
@@ -221,7 +221,7 @@ public:
         layout->setContentsMargins(0, 0, 0, 0);
         layout->setColumnStretch(1, 2);
 
-        QList<Utils::Id> languageList = Utils::toList(ToolChainManager::allLanguages());
+        QList<Utils::Id> languageList = ToolChainManager::allLanguages();
         Utils::sort(languageList, [](Utils::Id l1, Utils::Id l2) {
             return ToolChainManager::displayNameOfLanguageId(l1)
                     < ToolChainManager::displayNameOfLanguageId(l2);
diff --git a/src/plugins/projectexplorer/toolchain.cpp b/src/plugins/projectexplorer/toolchain.cpp
index b344f325627..220f24e0ac7 100644
--- a/src/plugins/projectexplorer/toolchain.cpp
+++ b/src/plugins/projectexplorer/toolchain.cpp
@@ -514,7 +514,7 @@ ToolChain *ToolChainFactory::createToolChain(Utils::Id toolChainType)
     return nullptr;
 }
 
-QSet<Utils::Id> ToolChainFactory::supportedLanguages() const
+QList<Utils::Id> ToolChainFactory::supportedLanguages() const
 {
     return m_supportsAllLanguages ? ToolChainManager::allLanguages() : m_supportedLanguages;
 }
@@ -529,7 +529,7 @@ void ToolChainFactory::setSupportedToolChainType(const Utils::Id &supportedToolC
     m_supportedToolChainType = supportedToolChain;
 }
 
-void ToolChainFactory::setSupportedLanguages(const QSet<Utils::Id> &supportedLanguages)
+void ToolChainFactory::setSupportedLanguages(const QList<Utils::Id> &supportedLanguages)
 {
     m_supportedLanguages = supportedLanguages;
 }
diff --git a/src/plugins/projectexplorer/toolchain.h b/src/plugins/projectexplorer/toolchain.h
index c1befe69b60..9cd512a1847 100644
--- a/src/plugins/projectexplorer/toolchain.h
+++ b/src/plugins/projectexplorer/toolchain.h
@@ -39,7 +39,6 @@
 #include <utils/id.h>
 
 #include <QObject>
-#include <QSet>
 #include <QStringList>
 #include <QVariantMap>
 
@@ -221,14 +220,14 @@ public:
 
     static ToolChain *createToolChain(Utils::Id toolChainType);
 
-    QSet<Utils::Id> supportedLanguages() const;
+    QList<Utils::Id> supportedLanguages() const;
 
     void setUserCreatable(bool userCreatable);
 
 protected:
     void setDisplayName(const QString &name) { m_displayName = name; }
     void setSupportedToolChainType(const Utils::Id &supportedToolChainType);
-    void setSupportedLanguages(const QSet<Utils::Id> &supportedLanguages);
+    void setSupportedLanguages(const QList<Utils::Id> &supportedLanguages);
     void setSupportsAllLanguages(bool supportsAllLanguages);
     void setToolchainConstructor(const std::function<ToolChain *()> &constructor);
 
@@ -248,7 +247,7 @@ protected:
 private:
     QString m_displayName;
     Utils::Id m_supportedToolChainType;
-    QSet<Utils::Id> m_supportedLanguages;
+    QList<Utils::Id> m_supportedLanguages;
     bool m_supportsAllLanguages = false;
     bool m_userCreatable = false;
     std::function<ToolChain *()> m_toolchainConstructor;
diff --git a/src/plugins/projectexplorer/toolchainmanager.cpp b/src/plugins/projectexplorer/toolchainmanager.cpp
index ff1fd2f0e8e..dec25e58668 100644
--- a/src/plugins/projectexplorer/toolchainmanager.cpp
+++ b/src/plugins/projectexplorer/toolchainmanager.cpp
@@ -227,9 +227,9 @@ void ToolChainManager::deregisterToolChain(ToolChain *tc)
     delete tc;
 }
 
-QSet<Utils::Id> ToolChainManager::allLanguages()
+QList<Id> ToolChainManager::allLanguages()
 {
-    return Utils::transform<QSet>(d->m_languages, &LanguageDisplayPair::id);
+    return Utils::transform<QList>(d->m_languages, &LanguageDisplayPair::id);
 }
 
 bool ToolChainManager::registerLanguage(const Utils::Id &language, const QString &displayName)
diff --git a/src/plugins/projectexplorer/toolchainmanager.h b/src/plugins/projectexplorer/toolchainmanager.h
index aa875092bb9..b99e268403a 100644
--- a/src/plugins/projectexplorer/toolchainmanager.h
+++ b/src/plugins/projectexplorer/toolchainmanager.h
@@ -71,7 +71,7 @@ public:
     static bool registerToolChain(ToolChain *tc);
     static void deregisterToolChain(ToolChain *tc);
 
-    static QSet<Utils::Id> allLanguages();
+    static QList<Utils::Id> allLanguages();
     static bool registerLanguage(const Utils::Id &language, const QString &displayName);
     static QString displayNameOfLanguageId(const Utils::Id &id);
     static bool isLanguageSupported(const Utils::Id &id);
diff --git a/src/plugins/projectexplorer/toolchainoptionspage.cpp b/src/plugins/projectexplorer/toolchainoptionspage.cpp
index c7d8b1c575e..b27bc178ea3 100644
--- a/src/plugins/projectexplorer/toolchainoptionspage.cpp
+++ b/src/plugins/projectexplorer/toolchainoptionspage.cpp
@@ -191,7 +191,7 @@ public:
         m_addButton = new QPushButton(ToolChainOptionsPage::tr("Add"), this);
         auto addMenu = new QMenu;
         foreach (ToolChainFactory *factory, m_factories) {
-            QList<Utils::Id> languages = Utils::toList(factory->supportedLanguages());
+            QList<Utils::Id> languages = factory->supportedLanguages();
             if (languages.isEmpty())
                 continue;