diff --git a/libc/bionic/poll.cpp b/libc/bionic/poll.cpp
index d267229..23ef90a 100644
--- a/libc/bionic/poll.cpp
+++ b/libc/bionic/poll.cpp
@@ -26,6 +26,7 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
 #include <errno.h>
 #include <sys/poll.h>
 #include <sys/select.h>