diff --git a/src/runcore/cores.c b/src/runcore/cores.c
index 06c3a0ccda..5727831bb0 100644
--- a/src/runcore/cores.c
+++ b/src/runcore/cores.c
@@ -260,15 +260,10 @@ next opcode, or examine and manipulate data from the executing program.
 #  include "../jit.h"
 #endif
 
-#if defined(CLOCK_PROCESS_CPUTIME_ID)
-#  define CLOCK_BEST CLOCK_PROCESS_CPUTIME_ID
-#elif defined(CLOCK_PROF)
-#  define CLOCK_BEST CLOCK_PROF
-#else
-#  define CLOCK_BEST CLOCK_REALTIME
+#ifdef WIN32
+#  define getpid _getpid
 #endif
 
-
 /* HEADERIZER HFILE: include/parrot/runcore_api.h */
 
 /* HEADERIZER BEGIN: static */