diff --git a/libc/tzcode/localtime.c b/libc/tzcode/localtime.c
index f0fd9e3..4dd7ab0 100644
--- a/libc/tzcode/localtime.c
+++ b/libc/tzcode/localtime.c
@@ -2293,7 +2293,7 @@
 }
 
 // Non-standard API: mktime(3) but with an explicit timezone parameter.
-time_t mktime_tz(struct tm* const tmp, const char* tz) {
+time_t __attribute__((visibility("default"))) mktime_tz(struct tm* const tmp, const char* tz) {
   struct state* st = malloc(sizeof(*st));
   time_t return_value;
 
@@ -2310,7 +2310,7 @@
 }
 
 // Non-standard API: localtime(3) but with an explicit timezone parameter.
-void localtime_tz(const time_t* const timep, struct tm* tmp, const char* tz) {
+void __attribute__((visibility("default"))) localtime_tz(const time_t* const timep, struct tm* tmp, const char* tz) {
   struct state* st = malloc(sizeof(*st));
 
   if (st == NULL)