diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9041e03..16b42a7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,8 +13,6 @@ set(libobjc_VERSION 4.6)
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fexceptions")
 # Build configuration
 add_definitions( -DGNUSTEP -D__OBJC_RUNTIME_INTERNAL__=1)
-# Probably not needed anymore?
-add_definitions( -D_XOPEN_SOURCE=700 -D__BSD_VISIBLE=1 -D_BSD_SOURCE=1)
 
 set(libobjc_ASM_SRCS 
 	block_trampolines.S