diff --git a/libc/include/time.h b/libc/include/time.h
index 0587a2d..34a53b2 100644
--- a/libc/include/time.h
+++ b/libc/include/time.h
@@ -31,6 +31,7 @@
 
 #include <sys/cdefs.h>
 #include <sys/time.h>
+#include <xlocale.h>
 
 __BEGIN_DECLS
 
@@ -75,6 +76,7 @@
 
 extern char* strptime(const char*, const char*, struct tm*) __LIBC_ABI_PUBLIC__;
 extern size_t strftime(char*, size_t, const char*, const struct tm*) __LIBC_ABI_PUBLIC__;
+extern size_t strftime_l(char *, size_t, const char *, const struct tm *, locale_t) __LIBC_ABI_PUBLIC__;
 
 extern char* ctime(const time_t*) __LIBC_ABI_PUBLIC__;
 extern char* ctime_r(const time_t*, char*) __LIBC_ABI_PUBLIC__;