diff --git a/cmake_unofficial/CMakeLists.txt b/cmake_unofficial/CMakeLists.txt
index bb7ab5f..4c0878a 100644
--- a/cmake_unofficial/CMakeLists.txt
+++ b/cmake_unofficial/CMakeLists.txt
@@ -69,14 +69,17 @@ endif()
 #warnings
 
 ADD_DEFINITIONS("-Wall")
+if(CMAKE_COMPILER_IS_GNUCXX)
 ADD_DEFINITIONS("-Wextra")
 ADD_DEFINITIONS("-Wundef")
 ADD_DEFINITIONS("-Wshadow")
 ADD_DEFINITIONS("-Wcast-align")
 ADD_DEFINITIONS("-Wstrict-prototypes")
+endif(CMAKE_COMPILER_IS_GNUCXX)
 ADD_DEFINITIONS("-std=c99")
 ADD_DEFINITIONS("-DLZ4_VERSION=\"${CPACK_PACKAGE_VERSION_PATCH}\"")
 INCLUDE_DIRECTORIES (${LZ4_DIR})
 
 
 
+