diff --git a/CMakeLists.txt b/CMakeLists.txt
index 97171f1254..f61f8082fa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -198,11 +198,13 @@ if(MSVC)
         endforeach(flag_var)
     endif(BUILD_WITH_STATIC_CRT)
 
-	include(ProcessorCount)
-	ProcessorCount(N)
-	if(NOT N EQUAL 0)
-		SET(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   /MP${N} ")
-		SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP${N} ")
+	if(NOT ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} LESS 2.8 AND NOT ${CMAKE_MINOR_VERSION}.${CMAKE_PATCH_VERSION} LESS 8.6)
+		include(ProcessorCount)
+		ProcessorCount(N)
+		if(NOT N EQUAL 0)
+			SET(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   /MP${N} ")
+			SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP${N} ")
+		endif()
 	endif()
 
     if(NOT BUILD_WITH_DEBUG_INFO)