diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3518a68ac52..dac209765a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -560,6 +560,10 @@ include_directories( ${LLVM_INCLUDE_DIR} ${LLVM_MAIN_INCLUDE_DIR})
 if(LLVM_USE_HOST_TOOLS)
   include(CrossCompile)
 endif(LLVM_USE_HOST_TOOLS)
+if(LLVM_TARGET_IS_CROSSCOMPILE_HOST)
+# Dummy use to avoid CMake Wraning: Manually-specified variables were not used
+# (this is a variable that CrossCompile sets on recursive invocations)
+endif()
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
   # On FreeBSD, /usr/local/* is not used by default. In order to build LLVM
diff --git a/cmake/modules/CrossCompile.cmake b/cmake/modules/CrossCompile.cmake
index 76a3078a544..c136dfaa612 100644
--- a/cmake/modules/CrossCompile.cmake
+++ b/cmake/modules/CrossCompile.cmake
@@ -19,6 +19,7 @@ function(llvm_create_cross_target_internal target_name toochain buildtype)
   add_custom_command(OUTPUT ${LLVM_${target_name}_BUILD}/CMakeCache.txt
     COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}"
         ${CROSS_TOOLCHAIN_FLAGS_${target_name}} ${CMAKE_SOURCE_DIR}
+        -DLLVM_TARGET_IS_CROSSCOMPILE_HOST=TRUE
     WORKING_DIRECTORY ${LLVM_${target_name}_BUILD}
     DEPENDS ${LLVM_${target_name}_BUILD}
     COMMENT "Configuring ${target_name} LLVM...")
@@ -43,6 +44,7 @@ function(llvm_create_cross_target_internal target_name toochain buildtype)
     execute_process(COMMAND ${CMAKE_COMMAND} ${build_type_flags}
         -G "${CMAKE_GENERATOR}" -DLLVM_TARGETS_TO_BUILD=${LLVM_TARGETS_TO_BUILD}
         ${CROSS_TOOLCHAIN_FLAGS_${target_name}} ${CMAKE_SOURCE_DIR}
+        -DLLVM_TARGET_IS_CROSSCOMPILE_HOST=TRUE
       WORKING_DIRECTORY ${LLVM_${target_name}_BUILD} )
   endif(NOT IS_DIRECTORY ${LLVM_${target_name}_BUILD})