diff --git a/lib/libc/gen/sched_getaffinity.c b/lib/libc/gen/sched_getaffinity.c
--- a/lib/libc/gen/sched_getaffinity.c
+++ b/lib/libc/gen/sched_getaffinity.c
@@ -38,9 +38,11 @@
 sched_getaffinity(pid_t pid, size_t cpusetsz, cpuset_t *cpuset)
 {
 	cpuwhich_t which;
-	int error;
+	int error, osrel;
 
-	if (__getosreldate() < P_OSREL_TIDPID) {
+	osrel = __getosreldate();
+	if (osrel < P_OSREL_TIDPID_13 || (osrel < P_OSREL_TIDPID &&
+	    P_OSREL_MAJOR(osrel) == P_OSREL_MAJOR(P_OSREL_TIDPID))) {
 		if (pid == 0 || pid > _PID_MAX)
 			which = CPU_WHICH_TID;
 		else
diff --git a/lib/libc/gen/sched_setaffinity.c b/lib/libc/gen/sched_setaffinity.c
--- a/lib/libc/gen/sched_setaffinity.c
+++ b/lib/libc/gen/sched_setaffinity.c
@@ -41,10 +41,12 @@
 	static int mp_maxid;
 	cpuwhich_t which;
 	cpuset_t c;
-	int error, lbs, cpu;
+	int error, lbs, cpu, osrel;
 	size_t len, sz;
 
-	if (__getosreldate() < P_OSREL_TIDPID) {
+        osrel = __getosreldate();
+	if (osrel < P_OSREL_TIDPID_13 || (osrel < P_OSREL_TIDPID &&
+	    P_OSREL_MAJOR(osrel) == P_OSREL_MAJOR(P_OSREL_TIDPID))) {
 		if (pid == 0 || pid > _PID_MAX)
 			which = CPU_WHICH_TID;
 		else
diff --git a/sys/sys/param.h b/sys/sys/param.h
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -92,6 +92,7 @@
 #define	P_OSREL_CK_INODE		1300005
 #define	P_OSREL_POWERPC_NEW_AUX_ARGS	1300070
 #define	P_OSREL_TIDPID			1400079
+#define	P_OSREL_TIDPID_13		1302501
 
 #define	P_OSREL_MAJOR(x)		((x) / 100000)
 #endif