diff --git a/miniupnpc/CMakeLists.txt b/miniupnpc/CMakeLists.txt
index 7fe7fcf..e1803de 100644
--- a/miniupnpc/CMakeLists.txt
+++ b/miniupnpc/CMakeLists.txt
@@ -29,7 +29,7 @@ if (NOT WIN32)
   target_compile_definitions(miniupnpc-private INTERFACE
     MINIUPNPC_SET_SOCKET_TIMEOUT
     _BSD_SOURCE _DEFAULT_SOURCE)
-  if (NOT CMAKE_SYSTEM_NAME STREQUAL "Darwin" AND NOT CMAKE_SYSTEM_NAME STREQUAL "FreeBSD" AND NOT CMAKE_SYSTEM_NAME STREQUAL "SunOS")
+  if (NOT APPLE AND NOT CMAKE_SYSTEM_NAME STREQUAL "FreeBSD" AND NOT CMAKE_SYSTEM_NAME STREQUAL "SunOS")
     # add_definitions (-D_POSIX_C_SOURCE=200112L)
     target_compile_definitions(miniupnpc-private INTERFACE _XOPEN_SOURCE=600)
   endif ()
@@ -37,7 +37,7 @@ else ()
   target_compile_definitions(miniupnpc-private INTERFACE _WIN32_WINNT=0x0501) # XP or higher for getnameinfo and friends
 endif ()
 
-if (CMAKE_SYSTEM_NAME STREQUAL "Darwin")
+if (APPLE)
   target_compile_definitions(miniupnpc-private INTERFACE _DARWIN_C_SOURCE)
 endif ()