diff --git a/src/plugins/cmakeprojectmanager/servermodereader.cpp b/src/plugins/cmakeprojectmanager/servermodereader.cpp
index 27bb31d1c32..796ec73886f 100644
--- a/src/plugins/cmakeprojectmanager/servermodereader.cpp
+++ b/src/plugins/cmakeprojectmanager/servermodereader.cpp
@@ -470,6 +470,8 @@ ServerModeReader::Target *ServerModeReader::extractTargetData(const QVariantMap
         target->fileGroups.append(extractFileGroupData(fgData, srcDir, target));
     }
 
+    fixTarget(target);
+
     m_targets.append(target);
     return target;
 }
@@ -548,6 +550,49 @@ void ServerModeReader::extractCacheData(const QVariantMap &data)
     m_cmakeCache = config;
 }
 
+void ServerModeReader::fixTarget(ServerModeReader::Target *target) const
+{
+    QHash<QString, const FileGroup *> languageFallbacks;
+
+    for (const FileGroup *group : Utils::asConst(target->fileGroups)) {
+        if (group->includePaths.isEmpty() && group->compileFlags.isEmpty()
+                && group->defines.isEmpty())
+            continue;
+
+        const FileGroup *fallback = languageFallbacks.value(group->language);
+        if (!fallback || fallback->sources.count() < group->sources.count())
+            languageFallbacks.insert(group->language, group);
+    }
+
+    if (!languageFallbacks.value(""))
+        return; // No empty language groups found, no need to proceed.
+
+    const FileGroup *fallback = languageFallbacks.value("CXX");
+    if (!fallback)
+        fallback = languageFallbacks.value("C");
+    if (!fallback)
+        fallback = languageFallbacks.value("");
+
+    if (!fallback)
+        return;
+
+    for (auto it = target->fileGroups.begin(); it != target->fileGroups.end(); ++it) {
+        if (!(*it)->language.isEmpty())
+            continue;
+        (*it)->language = fallback->language.isEmpty() ? "CXX" : fallback->language;
+
+        if (*it == fallback
+                || !(*it)->includePaths.isEmpty() || !(*it)->defines.isEmpty()
+                || !(*it)->compileFlags.isEmpty())
+            continue;
+
+        for (const IncludePath *ip : fallback->includePaths)
+            (*it)->includePaths.append(new IncludePath(*ip));
+        (*it)->defines = fallback->defines;
+        (*it)->compileFlags = fallback->compileFlags;
+    }
+}
+
 QHash<Utils::FileName, ProjectNode *>
 ServerModeReader::addCMakeLists(CMakeProjectNode *root, const QList<FileNode *> &cmakeLists)
 {
diff --git a/src/plugins/cmakeprojectmanager/servermodereader.h b/src/plugins/cmakeprojectmanager/servermodereader.h
index 3b1202c009a..0c3a3c2fd8c 100644
--- a/src/plugins/cmakeprojectmanager/servermodereader.h
+++ b/src/plugins/cmakeprojectmanager/servermodereader.h
@@ -113,6 +113,8 @@ private:
     void extractCMakeInputsData(const QVariantMap &data);
     void extractCacheData(const QVariantMap &data);
 
+    void fixTarget(Target *target) const;
+
     QHash<Utils::FileName, ProjectExplorer::ProjectNode *>
     addCMakeLists(CMakeProjectNode *root, const QList<ProjectExplorer::FileNode *> &cmakeLists);
     void addProjects(const QHash<Utils::FileName, ProjectExplorer::ProjectNode *> &cmakeListsNodes,