diff --git a/languages/plugins/custom-definesandincludes/definesandincludesmanager.cpp b/languages/plugins/custom-definesandincludes/definesandincludesmanager.cpp
index ebceb4dc96..df1be68253 100644
--- a/languages/plugins/custom-definesandincludes/definesandincludesmanager.cpp
+++ b/languages/plugins/custom-definesandincludes/definesandincludesmanager.cpp
@@ -1,321 +1,331 @@
 /*
  * This file is part of KDevelop
  *
  * Copyright 2014 Sergey Kalinichev <kalinichev.so.0@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  */
 
 #include "definesandincludesmanager.h"
 
 #include "kcm_widget/definesandincludesconfigpage.h"
 #include "compilerprovider/compilerprovider.h"
 #include "compilerprovider/widget/compilerswidget.h"
 #include "noprojectincludesanddefines/noprojectincludepathsmanager.h"
 
 #include <interfaces/icore.h>
 #include <interfaces/iprojectcontroller.h>
 #include <interfaces/iproject.h>
 #include <project/interfaces/ibuildsystemmanager.h>
 #include <project/projectmodel.h>
 
 #include <KPluginFactory>
 #include <KAboutData>
 
 #include <QThread>
 #include <QCoreApplication>
 
 #include <algorithm>
 
 using namespace KDevelop;
 
 namespace
 {
 ///@return: The ConfigEntry, with includes/defines from @p paths for all parent folders of @p item.
 static ConfigEntry findConfigForItem(QList<ConfigEntry> paths, const KDevelop::ProjectBaseItem* item)
 {
     ConfigEntry ret;
 
     const Path itemPath = item->path();
     const Path rootDirectory = item->project()->path();
     Path closestPath;
 
     std::sort(paths.begin(), paths.end(), [] (const ConfigEntry& lhs, const ConfigEntry& rhs) {
         // sort in reverse order to do a bottom-up search
         return lhs.path > rhs.path;
     });
 
     for (const ConfigEntry & entry : paths) {
         Path targetDirectory = rootDirectory;
         // note: a dot represents the project root
         if (entry.path != ".") {
             targetDirectory.addPath(entry.path);
         }
 
         if (targetDirectory == itemPath || targetDirectory.isParentOf(itemPath)) {
             ret.includes += entry.includes;
 
             for (auto it = entry.defines.constBegin(); it != entry.defines.constEnd(); it++) {
                 if (!ret.defines.contains(it.key())) {
                     ret.defines[it.key()] = it.value();
                 }
             }
 
             if (targetDirectory.segments().size() > closestPath.segments().size()) {
                 ret.parserArguments = entry.parserArguments;
                 closestPath = targetDirectory;
             }
         }
     }
     ret.includes.removeDuplicates();
 
     Q_ASSERT(!ret.parserArguments.cppArguments.isEmpty());
     Q_ASSERT(!ret.parserArguments.cArguments.isEmpty());
 
     return ret;
 }
 
 void merge(Defines* target, const Defines& source)
 {
     if (target->isEmpty()) {
         *target = source;
         return;
     }
 
     for (auto it = source.constBegin(); it != source.constEnd(); ++it) {
         target->insert(it.key(), it.value());
     }
 }
 
 }
 
 K_PLUGIN_FACTORY_WITH_JSON(DefinesAndIncludesManagerFactory, "kdevdefinesandincludesmanager.json", registerPlugin<DefinesAndIncludesManager>(); )
 
 DefinesAndIncludesManager::DefinesAndIncludesManager( QObject* parent, const QVariantList& )
     : IPlugin("kdevdefinesandincludesmanager", parent )
     , m_settings(SettingsManager::globalInstance())
     , m_noProjectIPM(new NoProjectIncludePathsManager())
 {
     KDEV_USE_EXTENSION_INTERFACE(IDefinesAndIncludesManager);
     registerProvider(m_settings->provider());
 }
 
 DefinesAndIncludesManager::~DefinesAndIncludesManager() = default;
 
 Defines DefinesAndIncludesManager::defines( ProjectBaseItem* item, Type type  ) const
 {
     Q_ASSERT(QThread::currentThread() == qApp->thread());
 
     if (!item) {
         return m_settings->provider()->defines(nullptr);
     }
 
     Defines defines;
 
     for (auto provider : m_providers) {
         if (provider->type() & type) {
             merge(&defines, provider->defines(item));
         }
     }
 
     if ( type & ProjectSpecific ) {
         auto buildManager = item->project()->buildSystemManager();
         if ( buildManager ) {
             merge(&defines, buildManager->defines(item));
         }
     }
 
     // Manually set defines have the highest priority and overwrite values of all other types of defines.
     if (type & UserDefined) {
         auto cfg = item->project()->projectConfiguration().data();
 
         merge(&defines, findConfigForItem(m_settings->readPaths(cfg), item).defines);
     }
 
     merge(&defines, m_noProjectIPM->includesAndDefines(item->path().path()).second);
 
     return defines;
 }
 
 Path::List DefinesAndIncludesManager::includes( ProjectBaseItem* item, Type type ) const
 {
     Q_ASSERT(QThread::currentThread() == qApp->thread());
 
     if (!item) {
         return m_settings->provider()->includes(nullptr);
     }
 
     Path::List includes;
 
     if (type & UserDefined) {
         auto cfg = item->project()->projectConfiguration().data();
 
         includes += KDevelop::toPathList(findConfigForItem(m_settings->readPaths(cfg), item).includes);
     }
 
     if ( type & ProjectSpecific ) {
         auto buildManager = item->project()->buildSystemManager();
         if ( buildManager ) {
             includes += buildManager->includeDirectories(item);
         }
     }
 
     for (auto provider : m_providers) {
-        if (provider->type() & type) {
-            includes += provider->includes(item);
+        if ( !(provider->type() & type) ) {
+            continue;
+        }
+        auto newItems = provider->includes(item);
+        if ( provider->type() & DefinesAndIncludesManager::CompilerSpecific ) {
+            // If an item occurs in the "compiler specific" list, but was previously supplied
+            // in the user include path list already, remove it from there.
+            // Re-ordering the system include paths causes confusion in some cases.
+            Q_FOREACH (const auto& x, newItems ) {
+                includes.removeAll(x);
+            }
         }
+        includes += newItems;
     }
 
     includes += m_noProjectIPM->includesAndDefines(item->path().path()).first;
 
     return includes;
 }
 
 bool DefinesAndIncludesManager::unregisterProvider(IDefinesAndIncludesManager::Provider* provider)
 {
     int idx = m_providers.indexOf(provider);
     if (idx != -1) {
         m_providers.remove(idx);
         return true;
     }
 
     return false;
 }
 
 void DefinesAndIncludesManager::registerProvider(IDefinesAndIncludesManager::Provider* provider)
 {
     Q_ASSERT(provider);
     if (m_providers.contains(provider)) {
         return;
     }
 
     m_providers.push_back(provider);
 }
 
 Defines DefinesAndIncludesManager::defines(const QString& path) const
 {
     Defines ret = m_settings->provider()->defines(nullptr);
     merge(&ret, m_noProjectIPM->includesAndDefines(path).second);
     return ret;
 }
 
 Path::List DefinesAndIncludesManager::includes(const QString& path) const
 {
     return m_settings->provider()->includes(nullptr) 
            + m_noProjectIPM->includesAndDefines(path).first;
 }
 
 void DefinesAndIncludesManager::openConfigurationDialog(const QString& pathToFile)
 {
     if (auto project = KDevelop::ICore::self()->projectController()->findProjectForUrl(QUrl::fromLocalFile(pathToFile))) {
         KDevelop::ICore::self()->projectController()->configureProject(project);
     } else {
         m_noProjectIPM->openConfigurationDialog(pathToFile);
     }
 }
 
 Path::List DefinesAndIncludesManager::includesInBackground(const QString& path) const
 {
     Path::List includes;
 
     for (auto provider: m_backgroundProviders) {
         includes += provider->includesInBackground(path);
     }
 
     return includes;
 }
 
 Defines DefinesAndIncludesManager::definesInBackground(const QString& path) const
 {
     QHash<QString, QString> defines;
 
     for (auto provider: m_backgroundProviders) {
         auto result = provider->definesInBackground(path);
         for (auto it = result.constBegin(); it != result.constEnd(); it++) {
             defines[it.key()] = it.value();
         }
     }
 
     merge(&defines, m_noProjectIPM->includesAndDefines(path).second);
 
     return defines;
 }
 
 bool DefinesAndIncludesManager::unregisterBackgroundProvider(IDefinesAndIncludesManager::BackgroundProvider* provider)
 {
     int idx = m_backgroundProviders.indexOf(provider);
     if (idx != -1) {
         m_backgroundProviders.remove(idx);
         return true;
     }
 
     return false;
 }
 
 void DefinesAndIncludesManager::registerBackgroundProvider(IDefinesAndIncludesManager::BackgroundProvider* provider)
 {
     Q_ASSERT(provider);
     if (m_backgroundProviders.contains(provider)) {
         return;
     }
 
     m_backgroundProviders.push_back(provider);
 }
 
 QString DefinesAndIncludesManager::parserArguments(KDevelop::ProjectBaseItem* item) const
 {
     Q_ASSERT(item);
 
     Q_ASSERT(QThread::currentThread() == qApp->thread());
 
     auto cfg = item->project()->projectConfiguration().data();
     const auto arguments = findConfigForItem(m_settings->readPaths(cfg), item).parserArguments;
     auto languageType = Utils::languageType(item->path(), arguments.parseAmbiguousAsCPP);
 
     return languageType == Utils::C ? arguments.cArguments : arguments.cppArguments;
 }
 
 QString DefinesAndIncludesManager::parserArguments(const QString& path) const
 {
     const auto args = m_settings->defaultParserArguments();
     auto languageType = Utils::languageType(Path(path));
     return languageType == Utils::C ? args.cArguments : args.cppArguments;
 }
 
 int DefinesAndIncludesManager::perProjectConfigPages() const
 {
     return 1;
 }
 
 ConfigPage* DefinesAndIncludesManager::perProjectConfigPage(int number, const ProjectConfigOptions& options, QWidget* parent)
 {
     if (number == 0) {
         return new DefinesAndIncludesConfigPage(this, options, parent);
     }
     return nullptr;
 }
 
 KDevelop::ConfigPage* DefinesAndIncludesManager::configPage(int number, QWidget* parent)
 {
     return number == 0 ? new CompilersWidget(parent) : nullptr;
 }
 
 int DefinesAndIncludesManager::configPages() const
 {
     return 1;
 }
 
 #include "definesandincludesmanager.moc"