diff --git a/libc/dlopen/dlopen.c b/libc/dlopen/dlopen.c
index 9be0c1f56..f1d75fcb5 100644
--- a/libc/dlopen/dlopen.c
+++ b/libc/dlopen/dlopen.c
@@ -45,6 +45,7 @@
 #include "libc/nt/memory.h"
 #include "libc/nt/runtime.h"
 #include "libc/proc/posix_spawn.h"
+#include "libc/runtime/internal.h"
 #include "libc/runtime/runtime.h"
 #include "libc/runtime/syslib.internal.h"
 #include "libc/serialize.h"
@@ -494,6 +495,8 @@ static uint8_t *movimm(uint8_t p[static 16], int reg, uint64_t val) {
 static void *foreign_thunk_sysv(void *func) {
   uint8_t *code, *p;
 #ifdef __x86_64__
+  // it is no longer needed
+  if (1) return func;
   // movabs $func,%rax
   // movabs $foreign_tramp,%r10
   // jmp *%r10
@@ -896,3 +899,17 @@ char *cosmo_dlerror(void) {
   STRACE("dlerror() → %#s", res);
   return res;
 }
+
+#ifdef __x86_64__
+static textstartup void dlopen_init() {
+  if (IsLinux() || IsFreebsd()) {
+    // switch from %fs to %gs for tls
+    struct CosmoTib *tib = __get_tls();
+    __morph_tls();
+    __set_tls(tib);
+  }
+}
+const void *const dlopen_ctor[] initarray = {
+    dlopen_init,
+};
+#endif
diff --git a/libc/runtime/set_tls-sysv.S b/libc/intrin/sys_set_tls.S
similarity index 100%
rename from libc/runtime/set_tls-sysv.S
rename to libc/intrin/sys_set_tls.S
diff --git a/libc/intrin/tlsmorphed.c b/libc/intrin/tlsmorphed.c
new file mode 100644
index 000000000..3a805571e
--- /dev/null
+++ b/libc/intrin/tlsmorphed.c
@@ -0,0 +1,21 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/runtime/internal.h"
+
+char __tls_morphed;
diff --git a/libc/runtime/clone.c b/libc/runtime/clone.c
index 72c76a94f..85d3db9df 100644
--- a/libc/runtime/clone.c
+++ b/libc/runtime/clone.c
@@ -48,6 +48,7 @@
 #include "libc/sock/internal.h"
 #include "libc/stdalign.internal.h"
 #include "libc/str/str.h"
+#include "libc/sysv/consts/arch.h"
 #include "libc/sysv/consts/clone.h"
 #include "libc/sysv/consts/futex.h"
 #include "libc/sysv/consts/nr.h"
@@ -63,6 +64,9 @@
 #define kMaxThreadIds 32768
 #define kMinThreadId  262144
 
+#define AMD64_SET_FSBASE 129
+#define AMD64_SET_GSBASE 131
+
 #define __NR_thr_new                      455
 #define __NR_clone_linux                  56
 #define __NR__lwp_create                  309
@@ -90,6 +94,7 @@ struct CloneArgs {
   void *arg;
 };
 
+int sys_set_tls();
 int __stack_call(void *, int, long, long, int (*)(void *, int), void *);
 
 static struct CloneArgs *AllocateCloneArgs(char *stk, size_t stksz) {
@@ -390,14 +395,14 @@ static int CloneNetbsd(int (*func)(void *, int), char *stk, size_t stksz,
 ////////////////////////////////////////////////////////////////////////////////
 // FREE BESIYATA DISHMAYA
 
-void bone(struct CloneArgs *wt) {
-  *wt->ztid = 0;
-}
-
 static wontreturn void FreebsdThreadMain(void *p) {
   struct CloneArgs *wt = p;
 #ifdef __aarch64__
   asm volatile("mov\tx28,%0" : /* no outputs */ : "r"(wt->tls));
+#elif defined(__x86_64__)
+  if (__tls_morphed) {
+    sys_set_tls(AMD64_SET_GSBASE, wt->tls);
+  }
 #endif
   *wt->ctid = wt->tid;
   wt->func(wt->arg, wt->tid);
@@ -534,6 +539,13 @@ static errno_t CloneSilicon(int (*fn)(void *, int), char *stk, size_t stksz,
 ////////////////////////////////////////////////////////////////////////////////
 // GNU/SYSTEMD
 
+struct LinuxCloneArgs {
+  int (*func)(void *, int);
+  void *arg;
+  char *tls;
+  int ctid;
+};
+
 int sys_clone_linux(int flags,   // rdi
                     long sp,     // rsi
                     int *ptid,   // rdx
@@ -542,24 +554,40 @@ int sys_clone_linux(int flags,   // rdi
                     void *func,  // r9
                     void *arg);  // 8(rsp)
 
+static int LinuxThreadEntry(void *arg, int tid) {
+  struct LinuxCloneArgs *wt = arg;
+  sys_set_tls(ARCH_SET_GS, wt->tls);
+  return wt->func(wt->arg, tid);
+}
+
 static int CloneLinux(int (*func)(void *arg, int rc), char *stk, size_t stksz,
                       int flags, void *arg, void *tls, int *ptid, int *ctid) {
   int rc;
   long sp;
+  struct LinuxCloneArgs *wt;
   sp = (intptr_t)(stk + stksz);
-  if (~flags & CLONE_CHILD_SETTID) {
-    flags |= CLONE_CHILD_SETTID;
-    sp -= sizeof(int);
-    sp = sp & -alignof(int);
-    ctid = (int *)sp;
-    sp -= 8;  // experiment
-  }
+  sp -= sizeof(struct LinuxCloneArgs);
   // align the stack
 #ifdef __aarch64__
   sp = sp & -128;  // for kernel 4.6 and earlier
 #else
   sp = sp & -16;
 #endif
+  wt = (struct LinuxCloneArgs *)sp;
+#ifdef __x86_64__
+  if ((flags & CLONE_SETTLS) && __tls_morphed) {
+    flags &= ~CLONE_SETTLS;
+    wt->arg = arg;
+    wt->tls = tls;
+    wt->func = func;
+    func = LinuxThreadEntry;
+    arg = wt;
+  }
+#endif
+  if (~flags & CLONE_CHILD_SETTID) {
+    flags |= CLONE_CHILD_SETTID;
+    ctid = &wt->ctid;
+  }
   if ((rc = sys_clone_linux(flags, sp, ptid, ctid, tls, func, arg)) >= 0) {
     // clone() is documented as setting ptid before return
     return 0;
diff --git a/libc/runtime/morph_tls.c b/libc/runtime/morph_tls.c
index 442b746e5..b780533ed 100644
--- a/libc/runtime/morph_tls.c
+++ b/libc/runtime/morph_tls.c
@@ -17,9 +17,9 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "ape/sections.internal.h"
-#include "libc/serialize.h"
 #include "libc/runtime/internal.h"
 #include "libc/runtime/runtime.h"
+#include "libc/serialize.h"
 #include "libc/thread/tls.h"
 
 typedef char xmm_t __attribute__((__vector_size__(16), __aligned__(1)));
@@ -55,11 +55,13 @@ privileged void __morph_tls(void) {
     // address 0x30 was promised to us, according to Go team
     // https://github.com/golang/go/issues/23617
     dis = 0x30;
-  } else {
+  } else if (IsWindows()) {
     // MSVC __declspec(thread) generates binary code for this
     // %gs:0x1480 abi. So long as TlsAlloc() isn't called >64
     // times we should be good.
     dis = 0x1480 + __tls_index * 8;
+  } else {
+    dis = 0;
   }
 
   // iterate over modifiable code looking for 9 byte instruction
@@ -112,6 +114,7 @@ privileged void __morph_tls(void) {
     }
   }
 
+  __tls_morphed = 1;
   __morph_end();
 #endif
 }
diff --git a/libc/runtime/set_tls.c b/libc/runtime/set_tls.c
index 3e87f0764..0dd8049c5 100644
--- a/libc/runtime/set_tls.c
+++ b/libc/runtime/set_tls.c
@@ -26,6 +26,9 @@
 #include "libc/thread/tls.h"
 #include "libc/thread/tls2.internal.h"
 
+#define AMD64_SET_FSBASE 129
+#define AMD64_SET_GSBASE 131
+
 int sys_set_tls();
 
 // we can't allow --ftrace here because cosmo_dlopen() calls this
@@ -37,9 +40,9 @@ dontinstrument textstartup void __set_tls(struct CosmoTib *tib) {
   if (IsWindows()) {
     asm("mov\t%1,%%gs:%0" : "=m"(*((long *)0x1480 + __tls_index)) : "r"(tib));
   } else if (IsFreebsd()) {
-    sys_set_tls(129 /*AMD64_SET_FSBASE*/, tib);
+    sys_set_tls(__tls_morphed ? AMD64_SET_GSBASE : AMD64_SET_FSBASE, tib);
   } else if (IsLinux()) {
-    sys_set_tls(ARCH_SET_FS, tib);
+    sys_set_tls(__tls_morphed ? ARCH_SET_GS : ARCH_SET_FS, tib);
   } else if (IsNetbsd()) {
     // netbsd has sysarch(X86_SET_FSBASE) but we can't use that because
     // signal handlers will cause it to be reset due to not setting the
diff --git a/libc/thread/tls.h b/libc/thread/tls.h
index 45f1a97ff..a713b050c 100644
--- a/libc/thread/tls.h
+++ b/libc/thread/tls.h
@@ -42,6 +42,7 @@ struct CosmoTib {
 };
 
 extern int __threaded;
+extern char __tls_morphed;
 extern unsigned __tls_index;
 
 char *_mktls(struct CosmoTib **);
diff --git a/libc/thread/tls2.internal.h b/libc/thread/tls2.internal.h
index 1bbe95c5e..b96693276 100644
--- a/libc/thread/tls2.internal.h
+++ b/libc/thread/tls2.internal.h
@@ -14,7 +14,11 @@ COSMOPOLITAN_C_START_
 __funline struct CosmoTib *__get_tls_privileged(void) {
   char *tib, *lin = (char *)0x30;
   if (IsLinux() || IsFreebsd() || IsNetbsd() || IsOpenbsd() || IsMetal()) {
-    asm("mov\t%%fs:(%1),%0" : "=a"(tib) : "r"(lin) : "memory");
+    if (!__tls_morphed) {
+      asm("mov\t%%fs:(%1),%0" : "=a"(tib) : "r"(lin) : "memory");
+    } else {
+      asm("mov\t%%gs:(%1),%0" : "=a"(tib) : "r"(lin) : "memory");
+    }
   } else {
     asm("mov\t%%gs:(%1),%0" : "=a"(tib) : "r"(lin) : "memory");
     if (IsWindows()) {