diff --git a/Source/cmQtAutomoc.cxx b/Source/cmQtAutomoc.cxx
index 942c7aba2..25614b862 100644
--- a/Source/cmQtAutomoc.cxx
+++ b/Source/cmQtAutomoc.cxx
@@ -195,6 +195,34 @@ void cmQtAutomoc::SetupAutomocTarget(cmTarget* target)
       }
     }
 
+
+  const char* qtIncDir = 0;
+  const char* qtCoreIncDir = 0;
+
+  // check whether ${QT_INCLUDE_DIR} is part of the implicit include dirs,
+  // see http://public.kitware.com/Bug/view.php?id=13667
+  bool qtIncludeDirMayHaveBeenRemoved = false;
+  if (makefile->IsSet("QT_INCLUDE_DIR"))
+    {
+    qtIncDir = makefile->GetDefinition("QT_INCLUDE_DIR");
+    std::string s =
+         makefile->GetSafeDefinition("CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES");
+    std::vector<std::string> implIncDirs;
+    cmSystemTools::ExpandListArgument(s, implIncDirs);
+    if (std::find(implIncDirs.begin(), implIncDirs.end(),std::string(qtIncDir))
+                                                          != implIncDirs.end())
+      {
+      qtIncludeDirMayHaveBeenRemoved = true;
+      if (makefile->IsSet("QT_QTCORE_INCLUDE_DIR"))
+        {
+        qtCoreIncDir = makefile->GetDefinition("QT_QTCORE_INCLUDE_DIR");
+        }
+      }
+    }
+
+  bool haveQtCoreIncDir = false;
+  bool haveQtIncDir = false;
+
   std::vector<std::string> includeDirs;
   cmGeneratorTarget gtgt(target);
   localGen->GetIncludeDirectories(includeDirs, &gtgt, "CXX");
@@ -207,6 +235,37 @@ void cmQtAutomoc::SetupAutomocTarget(cmTarget* target)
     _moc_incs += sep;
     sep = ";";
     _moc_incs += *incDirIt;
+
+    if (qtIncludeDirMayHaveBeenRemoved && qtCoreIncDir && qtIncDir) // #13667
+      {
+      if (*incDirIt == qtIncDir)
+        {
+        haveQtIncDir = true;
+        qtIncludeDirMayHaveBeenRemoved = false; // it's here, i.e. not removed
+        }
+      if (*incDirIt == qtCoreIncDir)
+        {
+        haveQtCoreIncDir = true;
+        }
+      }
+    }
+
+  // Some projects (kdelibs, phonon) query the compiler for its default
+  // include search dirs, and add those to
+  // CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES.
+  // These may include e.g./usr/lib/qt/include . This is typically also part
+  // of ${QT_INCLUDES}. If this directory is then contained in the implicit
+  // include dirs, it is removed from the include dirs returned from the
+  // target above. So we add ${QT_INCLUDE_DIR} manually for moc if we detected
+  // that ${QT_QTCORE_INCLUDE_DIR} is among the include dirs (there shouldn't
+  // be a way to use Qt4 without using ${QT_QTCORE_INCLUDE_DIR} I think.
+  // See #13646 and #13667.
+  if (qtIncludeDirMayHaveBeenRemoved && qtCoreIncDir && qtIncDir
+      && (haveQtCoreIncDir == true) && (haveQtIncDir == false))
+    {
+    _moc_incs += sep;
+    sep = ";";
+    _moc_incs += qtIncDir;
     }
 
   const char* tmp = target->GetProperty("COMPILE_DEFINITIONS");