diff --git a/libc/bionic/getcwd.cpp b/libc/bionic/getcwd.cpp
index a8bbcf3..bcd6a57 100644
--- a/libc/bionic/getcwd.cpp
+++ b/libc/bionic/getcwd.cpp
@@ -26,6 +26,7 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
 #include <errno.h>
 #include <malloc.h>
 #include <string.h>