diff --git a/winpr/libwinpr/synch/CMakeLists.txt b/winpr/libwinpr/synch/CMakeLists.txt
index fbc607292..3beea6d5a 100644
--- a/winpr/libwinpr/synch/CMakeLists.txt
+++ b/winpr/libwinpr/synch/CMakeLists.txt
@@ -55,7 +55,7 @@ set(${MODULE_PREFIX}_LIBS
 	${CMAKE_THREAD_LIBS_INIT}
 	${CMAKE_DL_LIBS})
 
-if(${CMAKE_SYSTEM_NAME} MATCHES SunOS)
+if((NOT WIN32) AND (NOT APPLE) AND (NOT ANDROID))
 	set(${MODULE_PREFIX}_LIBS ${${MODULE_PREFIX}_LIBS} rt)
 endif()