diff --git a/libc/arch-x86/bionic/clone.S b/libc/arch-x86/bionic/clone.S
new file mode 100644
index 0000000..361808d
--- /dev/null
+++ b/libc/arch-x86/bionic/clone.S
@@ -0,0 +1,50 @@
+#include <sys/linux-syscalls.h>
+
+.text
+
+/*
+ * int  __pthread_clone(int (*fn)(void*), void *tls, int flags,
+ *                      void *arg);
+ */
+.globl __pthread_clone
+.type __pthread_clone, @function
+.align 4
+__pthread_clone:
+        pushl   %ebx
+        pushl   %ecx
+        movl    16(%esp), %ecx
+        movl    20(%esp), %ebx
+
+        # insert arguments onto the child stack
+        movl    12(%esp), %eax
+        movl    %eax, -12(%ecx)
+        movl    24(%esp), %eax
+        movl    %eax, -8(%ecx)
+        lea     (%ecx), %eax
+        movl    %eax, -4(%ecx)
+
+        movl    $__NR_clone, %eax
+        int     $0x80
+        test    %eax, %eax
+        jns     1f
+
+        # an error occured, set errno and return -1
+        negl    %eax
+        call    __set_errno
+        orl     $-1, %eax
+        jmp     2f
+
+1:
+        jnz     2f
+
+        # we're in the child thread now, call __thread_entry
+        # with the appropriate arguments on the child stack
+        # we already placed most of them
+        subl    $16, %esp
+        jmp     __thread_entry
+        hlt
+
+2:
+        popl    %ecx
+        popl    %ebx
+        ret