diff --git a/comio/CMakeLists.txt b/comio/CMakeLists.txt
index 6dbe7748343382e0539ab1e8a64e1f65a23fcac9..ef8d5f703f87a4543a43eafc1ad24d4aa62d6e93 100644
--- a/comio/CMakeLists.txt
+++ b/comio/CMakeLists.txt
@@ -14,12 +14,12 @@ if(WIN32)
 	list(APPEND SOURCE comio_win32.c)
 else()
 	list(APPEND SOURCE comio_nix.c)
-	if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-		target_compile_definitions(comio PRIVATE SPEED_MACROS_ONLY)
-	endif()
 endif()
 
 add_library(comio OBJECT ${SOURCE})
+if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+	target_compile_definitions(comio PRIVATE SPEED_MACROS_ONLY)
+endif()
 target_include_directories(comio PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 
 target_link_libraries(comio xpdev)