diff --git a/lib/libsys/amd64/amd64_get_fsbase.c b/lib/libsys/amd64/amd64_get_fsbase.c
--- a/lib/libsys/amd64/amd64_get_fsbase.c
+++ b/lib/libsys/amd64/amd64_get_fsbase.c
@@ -30,7 +30,6 @@
  * SUCH DAMAGE.
  */
 
-#define _WANT_P_OSREL
 #include <sys/param.h>
 #include <machine/cpufunc.h>
 #include <machine/specialreg.h>
@@ -41,7 +40,6 @@
 static int
 amd64_get_fsbase_cpu(void **addr)
 {
-
 	*addr = (void *)rdfsbase();
 	return (0);
 }
@@ -49,15 +47,12 @@
 static int
 amd64_get_fsbase_syscall(void **addr)
 {
-
 	return (sysarch(AMD64_GET_FSBASE, addr));
 }
 
 DEFINE_UIFUNC(, int, amd64_get_fsbase, (void **))
 {
-
-	if (__getosreldate() >= P_OSREL_WRFSBASE &&
-	    (cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
+	if ((cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
 		return (amd64_get_fsbase_cpu);
 	return (amd64_get_fsbase_syscall);
 }
diff --git a/lib/libsys/amd64/amd64_get_gsbase.c b/lib/libsys/amd64/amd64_get_gsbase.c
--- a/lib/libsys/amd64/amd64_get_gsbase.c
+++ b/lib/libsys/amd64/amd64_get_gsbase.c
@@ -30,7 +30,6 @@
  * SUCH DAMAGE.
  */
 
-#define _WANT_P_OSREL
 #include <sys/param.h>
 #include <machine/cpufunc.h>
 #include <machine/specialreg.h>
@@ -41,7 +40,6 @@
 static int
 amd64_get_gsbase_cpu(void **addr)
 {
-
 	*addr = (void *)rdgsbase();
 	return (0);
 }
@@ -49,15 +47,12 @@
 static int
 amd64_get_gsbase_syscall(void **addr)
 {
-
 	return (sysarch(AMD64_GET_GSBASE, addr));
 }
 
 DEFINE_UIFUNC(, int, amd64_get_gsbase, (void **))
 {
-
-	if (__getosreldate() >= P_OSREL_WRFSBASE &&
-	    (cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
+	if ((cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
 		return (amd64_get_gsbase_cpu);
 	return (amd64_get_gsbase_syscall);
 }
diff --git a/lib/libsys/amd64/amd64_set_fsbase.c b/lib/libsys/amd64/amd64_set_fsbase.c
--- a/lib/libsys/amd64/amd64_set_fsbase.c
+++ b/lib/libsys/amd64/amd64_set_fsbase.c
@@ -30,7 +30,6 @@
  * SUCH DAMAGE.
  */
 
-#define _WANT_P_OSREL
 #include <sys/param.h>
 #include <machine/cpufunc.h>
 #include <machine/specialreg.h>
@@ -41,7 +40,6 @@
 static int
 amd64_set_fsbase_cpu(void *addr)
 {
-
 	wrfsbase((uintptr_t)addr);
 	return (0);
 }
@@ -49,15 +47,12 @@
 static int
 amd64_set_fsbase_syscall(void *addr)
 {
-
 	return (sysarch(AMD64_SET_FSBASE, &addr));
 }
 
 DEFINE_UIFUNC(, int, amd64_set_fsbase, (void *))
 {
-
-	if (__getosreldate() >= P_OSREL_WRFSBASE &&
-	    (cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
+	if ((cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
 		return (amd64_set_fsbase_cpu);
 	return (amd64_set_fsbase_syscall);
 }
diff --git a/lib/libsys/amd64/amd64_set_gsbase.c b/lib/libsys/amd64/amd64_set_gsbase.c
--- a/lib/libsys/amd64/amd64_set_gsbase.c
+++ b/lib/libsys/amd64/amd64_set_gsbase.c
@@ -30,7 +30,6 @@
  * SUCH DAMAGE.
  */
 
-#define _WANT_P_OSREL
 #include <sys/param.h>
 #include <machine/cpufunc.h>
 #include <machine/specialreg.h>
@@ -41,7 +40,6 @@
 static int
 amd64_set_gsbase_cpu(void *addr)
 {
-
 	wrgsbase((uintptr_t)addr);
 	return (0);
 }
@@ -49,15 +47,12 @@
 static int
 amd64_set_gsbase_syscall(void *addr)
 {
-
 	return (sysarch(AMD64_SET_GSBASE, &addr));
 }
 
 DEFINE_UIFUNC(, int, amd64_set_gsbase, (void *))
 {
-
-	if (__getosreldate() >= P_OSREL_WRFSBASE &&
-	    (cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
+	if ((cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
 		return (amd64_set_gsbase_cpu);
 	return (amd64_set_gsbase_syscall);
 }
diff --git a/libexec/rtld-elf/amd64/reloc.c b/libexec/rtld-elf/amd64/reloc.c
--- a/libexec/rtld-elf/amd64/reloc.c
+++ b/libexec/rtld-elf/amd64/reloc.c
@@ -526,8 +526,6 @@
 	}
 }
 
-int __getosreldate(void);
-
 void
 allocate_initial_tls(Obj_Entry *objs)
 {
@@ -548,8 +546,7 @@
 	 */
 	if (__getosreldate() >= P_OSREL_TLSBASE)
 		sysarch(AMD64_SET_TLSBASE, &addr);
-	else if (__getosreldate() >= P_OSREL_WRFSBASE &&
-	    (cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
+	else if ((cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
 		wrfsbase((uintptr_t)addr);
 	else
 		sysarch(AMD64_SET_FSBASE, &addr);
diff --git a/sys/sys/param.h b/sys/sys/param.h
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -97,7 +97,6 @@
 #define	P_OSREL_MAP_ANON		800104
 #define	P_OSREL_MAP_FSTRICT		1100036
 #define	P_OSREL_SHUTDOWN_ENOTCONN	1100077
-#define	P_OSREL_WRFSBASE		1200041
 #define	P_OSREL_CK_CYLGRP		1200046
 #define	P_OSREL_VMTOTAL64		1200054
 #define	P_OSREL_CK_SUPERBLOCK		1300000