diff --git a/Externals/Lua/CMakeLists.txt b/Externals/Lua/CMakeLists.txt
index fa6a1672f6..ec264a67de 100644
--- a/Externals/Lua/CMakeLists.txt
+++ b/Externals/Lua/CMakeLists.txt
@@ -1,4 +1,4 @@
-if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
+if(UNIX)
 	add_definitions(-DLUA_USE_LINUX)
 endif()