diff --git a/libc/include/time64.h b/libc/include/time64.h
index b4f1280..905669d 100644
--- a/libc/include/time64.h
+++ b/libc/include/time64.h
@@ -33,12 +33,7 @@
 
 #if defined(__LP64__)
 
-/* TODO: remove this when external/chromium_org is fixed. */
-#define time64_t time_t
-#define gmtime64_r gmtime_r
-#define localtime64_r localtime_r
-#define mktime64 mktime
-#define timegm64 timegm
+#error Your time_t is already 64-bit.
 
 #else
 
diff --git a/libc/tzcode/strftime.c b/libc/tzcode/strftime.c
index 1164a13..2a1db64 100644
--- a/libc/tzcode/strftime.c
+++ b/libc/tzcode/strftime.c
@@ -37,7 +37,12 @@
 #include "fcntl.h"
 #include "locale.h"
 #include <ctype.h>
+#if defined(__LP64__)
+#define time64_t time_t
+#define mktime64 mktime
+#else
 #include <time64.h>
+#endif
 #include "private/bionic_time.h"  /* for strftime_tz */
 
 /* struct lc_time_T is now defined as strftime_locale