diff --git a/libc/arch-x86/bionic/__set_tls.c b/libc/arch-x86/bionic/__set_tls.c
index e5e43b5..7ed4b01 100755
--- a/libc/arch-x86/bionic/__set_tls.c
+++ b/libc/arch-x86/bionic/__set_tls.c
@@ -83,6 +83,7 @@
     if (rc != 0)
     {
         /* could not set thread local area */
+        pthread_mutex_unlock(&_tls_desc_lock);
         return -1;
     }