diff --git a/src/plugins/projectexplorer/toolchain.cpp b/src/plugins/projectexplorer/toolchain.cpp
index 98df39036a9..ab53717e80c 100644
--- a/src/plugins/projectexplorer/toolchain.cpp
+++ b/src/plugins/projectexplorer/toolchain.cpp
@@ -44,6 +44,7 @@ using namespace Utils;
 static const char ID_KEY[] = "ProjectExplorer.ToolChain.Id";
 static const char DISPLAY_NAME_KEY[] = "ProjectExplorer.ToolChain.DisplayName";
 static const char AUTODETECT_KEY[] = "ProjectExplorer.ToolChain.Autodetect";
+static const char DETECTION_SOURCE_KEY[] = "ProjectExplorer.ToolChain.DetectionSource";
 static const char LANGUAGE_KEY_V1[] = "ProjectExplorer.ToolChain.Language"; // For QtCreator <= 4.2
 static const char LANGUAGE_KEY_V2[] = "ProjectExplorer.ToolChain.LanguageV2"; // For QtCreator > 4.2
 
@@ -82,6 +83,7 @@ public:
     Utils::Id m_typeId;
     Utils::Id m_language;
     Detection m_detection = ToolChain::UninitializedDetection;
+    QString m_detectionSource;
 
     ToolChain::MacrosCache m_predefinedMacrosCache;
     ToolChain::HeaderPathsCache m_headerPathsCache;
@@ -173,6 +175,11 @@ ToolChain::Detection ToolChain::detection() const
     return d->m_detection;
 }
 
+QString ToolChain::detectionSource() const
+{
+    return d->m_detectionSource;
+}
+
 QByteArray ToolChain::id() const
 {
     return d->m_id;
@@ -252,6 +259,7 @@ QVariantMap ToolChain::toMap() const
     result.insert(QLatin1String(ID_KEY), idToSave);
     result.insert(QLatin1String(DISPLAY_NAME_KEY), displayName());
     result.insert(QLatin1String(AUTODETECT_KEY), isAutoDetected());
+    result.insert(QLatin1String(DETECTION_SOURCE_KEY), d->m_detectionSource);
     // <Compatibility with QtC 4.2>
     int oldLanguageId = -1;
     if (language() == ProjectExplorer::Constants::C_LANGUAGE_ID)
@@ -282,6 +290,11 @@ void ToolChain::setDetection(ToolChain::Detection de)
     d->m_detection = de;
 }
 
+void ToolChain::setDetectionSource(const QString &source)
+{
+    d->m_detectionSource = source;
+}
+
 QString ToolChain::typeDisplayName() const
 {
     return d->m_typeDisplayName;
@@ -353,6 +366,7 @@ bool ToolChain::fromMap(const QVariantMap &data)
 
     const bool autoDetect = data.value(QLatin1String(AUTODETECT_KEY), false).toBool();
     d->m_detection = autoDetect ? AutoDetection : ManualDetection;
+    d->m_detectionSource = data.value(DETECTION_SOURCE_KEY).toString();
 
     if (data.contains(LANGUAGE_KEY_V2)) {
         // remove hack to trim language id in 4.4: This is to fix up broken language
diff --git a/src/plugins/projectexplorer/toolchain.h b/src/plugins/projectexplorer/toolchain.h
index 2c2a3c68b72..b3ad1484c58 100644
--- a/src/plugins/projectexplorer/toolchain.h
+++ b/src/plugins/projectexplorer/toolchain.h
@@ -100,6 +100,7 @@ public:
 
     bool isAutoDetected() const;
     Detection detection() const;
+    QString detectionSource() const;
 
     QByteArray id() const;
 
@@ -165,6 +166,7 @@ public:
 
     void setLanguage(Utils::Id language);
     void setDetection(Detection d);
+    void setDetectionSource(const QString &source);
 
     static Utils::LanguageVersion cxxLanguageVersion(const QByteArray &cplusplusMacroValue);
     static Utils::LanguageVersion languageVersion(const Utils::Id &language, const Macros &macros);