diff --git a/libc/upstream-freebsd/namespace.h b/libc/upstream-freebsd/namespace.h
index a3f850e..a980b57 100644
--- a/libc/upstream-freebsd/namespace.h
+++ b/libc/upstream-freebsd/namespace.h
@@ -17,4 +17,6 @@
 #ifndef _BIONIC_FREEBSD_NAMESPACE_H_included
 #define _BIONIC_FREEBSD_NAMESPACE_H_included
 
+__attribute__((visibility("hidden"))) char* _mktemp(char*);
+
 #endif