--- xnu/xnu-344.2/iokit/Kernel/IOPMPowerSourceList.cpp
+++ xnu/xnu-201.5/iokit/Kernel/IOPMPowerSourceList.cpp
@@ -19,6 +19,7 @@
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
+#include <stddef.h> 
 #include <IOKit/pwr_mgt/IOPM.h>
 #include <IOKit/pwr_mgt/IOPMPowerSourceList.h>
 #include <IOKit/pwr_mgt/IOPMPowerSource.h>