diff --git a/libc/bionic/legacy_32_bit_support.cpp b/libc/bionic/legacy_32_bit_support.cpp
index 50e4643ce..a10766471 100644
--- a/libc/bionic/legacy_32_bit_support.cpp
+++ b/libc/bionic/legacy_32_bit_support.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <errno.h>
 #include <fcntl.h>
 #include <stdarg.h>