diff --git a/libc/calls/ucontext.c b/libc/calls/ucontext.c
index a6227663bbd..d5ba75a94cc 100644
--- a/libc/calls/ucontext.c
+++ b/libc/calls/ucontext.c
@@ -34,7 +34,7 @@ int __tailcontext(const ucontext_t *);
  * @see getcontext()
  */
 int setcontext(const ucontext_t *uc) {
-  if (IsWindows()) {
+  if (IsWindows() || IsMetal()) {
     atomic_store_explicit(&__get_tls()->tib_sigmask, uc->uc_sigmask,
                           memory_order_release);
   } else {
@@ -44,7 +44,7 @@ int setcontext(const ucontext_t *uc) {
 }
 
 int __getcontextsig(ucontext_t *uc) {
-  if (IsWindows()) {
+  if (IsWindows() || IsMetal()) {
     uc->uc_sigmask =
         atomic_load_explicit(&__get_tls()->tib_sigmask, memory_order_acquire);
     return 0;
@@ -54,7 +54,7 @@ int __getcontextsig(ucontext_t *uc) {
 }
 
 int __swapcontextsig(ucontext_t *x, const ucontext_t *y) {
-  if (IsWindows()) {
+  if (IsWindows() || IsMetal()) {
     x->uc_sigmask = atomic_exchange_explicit(
         &__get_tls()->tib_sigmask, y->uc_sigmask, memory_order_acquire);
     return 0;
diff --git a/libc/intrin/mman.greg.c b/libc/intrin/mman.greg.c
index cb9274a1b56..8d7f17449a5 100644
--- a/libc/intrin/mman.greg.c
+++ b/libc/intrin/mman.greg.c
@@ -45,7 +45,7 @@
 #ifdef __x86_64__
 
 #define INVERT(x) (BANE + PHYSICAL((uintptr_t)(x)))
-#define NOPAGE    ((uint64_t) - 1)
+#define NOPAGE    ((uint64_t)-1)
 
 #define APE_STACK_VADDR                   \
   ({                                      \
@@ -69,9 +69,9 @@ texthead uint64_t __new_page(struct mman *mm) {
   if (p != NOPAGE) {
     uint64_t q;
     struct ReclaimedPage *rp = (struct ReclaimedPage *)(BANE + p);
-    unassert(p == (p & PAGE_TA));
+    /* unassert(p == (p & PAGE_TA)); */
     q = rp->next;
-    unassert(q == (q & PAGE_TA) || q == NOPAGE);
+    /* unassert(q == (q & PAGE_TA) || q == NOPAGE); */
     mm->frp = q;
     return p;
   }
@@ -200,7 +200,7 @@ void __ref_pages(struct mman *mm, uint64_t *pml4t, uint64_t ps, uint64_t size) {
  */
 static void __reclaim_page(struct mman *mm, uint64_t p) {
   struct ReclaimedPage *rp = (struct ReclaimedPage *)(BANE + p);
-  unassert(p == (p & PAGE_TA));
+  /* unassert(p == (p & PAGE_TA)); */
   rp->next = mm->frp;
   mm->frp = p;
 }
diff --git a/libc/intrin/pthread_mutex_lock.c b/libc/intrin/pthread_mutex_lock.c
index 0138974e62a..6fd2c6bfbb8 100644
--- a/libc/intrin/pthread_mutex_lock.c
+++ b/libc/intrin/pthread_mutex_lock.c
@@ -25,7 +25,6 @@
 #include "libc/runtime/internal.h"
 #include "libc/thread/lock.h"
 #include "libc/thread/thread.h"
-#include "libc/thread/tls.h"
 #include "third_party/nsync/mu.h"
 
 /**
diff --git a/libc/intrin/sig.c b/libc/intrin/sig.c
index 2bffeeb7b10..8679b811ddc 100644
--- a/libc/intrin/sig.c
+++ b/libc/intrin/sig.c
@@ -27,9 +27,12 @@
 struct Signals __sig;
 
 sigset_t __sig_block(void) {
-  if (IsWindows()) {
-    return atomic_exchange_explicit(&__get_tls()->tib_sigmask, -1,
-                                    memory_order_acquire);
+  if (IsWindows() || IsMetal()) {
+    if (__tls_enabled)
+      return atomic_exchange_explicit(&__get_tls()->tib_sigmask, -1,
+                                      memory_order_acquire);
+    else
+      return 0;
   } else {
     sigset_t res, neu = -1;
     sys_sigprocmask(SIG_SETMASK, &neu, &res);
@@ -38,10 +41,12 @@ sigset_t __sig_block(void) {
 }
 
 void __sig_unblock(sigset_t m) {
-  if (IsWindows()) {
-    atomic_store_explicit(&__get_tls()->tib_sigmask, m, memory_order_release);
-    if (_weaken(__sig_check)) {
-      _weaken(__sig_check)();
+  if (IsWindows() || IsMetal()) {
+    if (__tls_enabled) {
+      atomic_store_explicit(&__get_tls()->tib_sigmask, m, memory_order_release);
+      if (_weaken(__sig_check)) {
+        _weaken(__sig_check)();
+      }
     }
   } else {
     sys_sigprocmask(SIG_SETMASK, &m, 0);
diff --git a/libc/runtime/set_tls.c b/libc/runtime/set_tls.c
index 0f54e8d1285..a1d49789639 100644
--- a/libc/runtime/set_tls.c
+++ b/libc/runtime/set_tls.c
@@ -57,7 +57,7 @@ dontinstrument textstartup void __set_tls(struct CosmoTib *tib) {
     uint64_t val = (uint64_t)tib;
     asm volatile("wrmsr"
                  : /* no outputs */
-                 : "c"(MSR_IA32_FS_BASE), "a"((uint32_t)val),
+                 : "c"(MSR_IA32_GS_BASE), "a"((uint32_t)val),
                    "d"((uint32_t)(val >> 32)));
   }
 #elif defined(__aarch64__)
diff --git a/libc/thread/pthread_create.c b/libc/thread/pthread_create.c
index 9e01f26f62a..740d43cef01 100644
--- a/libc/thread/pthread_create.c
+++ b/libc/thread/pthread_create.c
@@ -118,7 +118,7 @@ static int PosixThread(void *arg, int tid) {
   // set long jump handler so pthread_exit can bring control back here
   if (!setjmp(pt->pt_exiter)) {
     sigdelset(&pt->pt_attr.__sigmask, SIGTHR);
-    if (IsWindows()) {
+    if (IsWindows() || IsMetal()) {
       atomic_store_explicit(&__get_tls()->tib_sigmask, pt->pt_attr.__sigmask,
                             memory_order_release);
     } else {