diff --git a/src/plugins/projectexplorer/kitinformation.cpp b/src/plugins/projectexplorer/kitinformation.cpp
index 1f9b7b6e6ac..7752c1b8f9d 100644
--- a/src/plugins/projectexplorer/kitinformation.cpp
+++ b/src/plugins/projectexplorer/kitinformation.cpp
@@ -239,6 +239,20 @@ void ToolChainKitInformation::upgrade(Kit *k)
             k->setSticky(ToolChainKitInformation::id(), k->isSticky(oldIdV2));
         }
     }
+
+    // upgrade 4.3-temporary-master-state to 4.3:
+    {
+        const QVariantMap valueMap = k->value(ToolChainKitInformation::id()).toMap();
+        QVariantMap result;
+        for (const QString &key : valueMap.keys()) {
+            const int pos = key.lastIndexOf('.');
+            if (pos >= 0)
+                result.insert(key.mid(pos + 1), valueMap.value(key));
+            else
+                result.insert(key, valueMap.value(key));
+        }
+        k->setValue(ToolChainKitInformation::id(), result);
+    }
 }
 
 void ToolChainKitInformation::fix(Kit *k)
diff --git a/src/plugins/projectexplorer/projectexplorerconstants.h b/src/plugins/projectexplorer/projectexplorerconstants.h
index 3adae9ef025..dab1f51f25c 100644
--- a/src/plugins/projectexplorer/projectexplorerconstants.h
+++ b/src/plugins/projectexplorer/projectexplorerconstants.h
@@ -210,8 +210,10 @@ const char BUILDSTEPS_DEPLOY[] = "ProjectExplorer.BuildSteps.Deploy";
 const char DEFAULT_DEPLOYCONFIGURATION_ID[] = "ProjectExplorer.DefaultDeployConfiguration";
 
 // Language
-const char C_LANGUAGE_ID[] = "ProjectExplorer.Language.C";
-const char CXX_LANGUAGE_ID[] = "ProjectExplorer.Language.Cxx";
+
+// Keep these short: These constants are exposed to the MacroExplorer!
+const char C_LANGUAGE_ID[] = "C";
+const char CXX_LANGUAGE_ID[] = "Cxx";
 
 // ToolChain TypeIds
 const char CLANG_TOOLCHAIN_TYPEID[] = "ProjectExplorer.ToolChain.Clang";
diff --git a/src/plugins/projectexplorer/toolchain.cpp b/src/plugins/projectexplorer/toolchain.cpp
index 0d72beb187a..7e867b0c472 100644
--- a/src/plugins/projectexplorer/toolchain.cpp
+++ b/src/plugins/projectexplorer/toolchain.cpp
@@ -262,10 +262,18 @@ bool ToolChain::fromMap(const QVariantMap &data)
     const bool autoDetect = data.value(QLatin1String(AUTODETECT_KEY), false).toBool();
     d->m_detection = autoDetect ? AutoDetectionFromSettings : ManualDetection;
 
-    if (data.contains(LANGUAGE_KEY_V2))
-        d->m_language = Core::Id::fromSetting(data.value(QLatin1String(LANGUAGE_KEY_V2)));
-    else if (data.contains(LANGUAGE_KEY_V1)) // Import from old settings
+    if (data.contains(LANGUAGE_KEY_V2)) {
+        // remove hack to trim language id in 4.4: This is to fix up broken language
+        // ids that happened in 4.3 master branch
+        const QString langId = data.value(QLatin1String(LANGUAGE_KEY_V2)).toString();
+        const int pos = langId.lastIndexOf('.');
+        if (pos >= 0)
+            d->m_language = Core::Id::fromString(langId.mid(pos + 1));
+        else
+            d->m_language = Core::Id::fromString(langId);
+    } else if (data.contains(LANGUAGE_KEY_V1)) { // Import from old settings
         d->m_language = Internal::fromLanguageV1(data.value(QLatin1String(LANGUAGE_KEY_V1)).toInt());
+    }
 
     if (!d->m_language.isValid())
         d->m_language = Core::Id(Constants::CXX_LANGUAGE_ID);