diff --git a/libc/arch-mips/bionic/vfork.S b/libc/arch-mips/bionic/vfork.S
index 1849624..7ccf70b 100644
--- a/libc/arch-mips/bionic/vfork.S
+++ b/libc/arch-mips/bionic/vfork.S
@@ -37,6 +37,14 @@
 	.set	noreorder
 	.cpload	t9
 
+	// __get_tls()[TLS_SLOT_THREAD_ID]->cached_pid_ = 0
+	.set	push
+	.set	mips32r2
+	rdhwr	v0, $29			// v0 = tls; kernel trap on mips32r1
+	.set	pop
+	lw	v0, REGSZ*1(v0)		// v0 = v0[TLS_SLOT_THREAD_ID ie 1]
+	sw	$0, REGSZ*2+4(v0)	// v0->cached_pid_ = 0
+
 	li	a0, (CLONE_VM | CLONE_VFORK | SIGCHLD)
 	li	a1, 0
 	li	a2, 0