diff --git a/libc/bionic/getcwd.cpp b/libc/bionic/getcwd.cpp
index c2a7e23..50487ec 100644
--- a/libc/bionic/getcwd.cpp
+++ b/libc/bionic/getcwd.cpp
@@ -26,7 +26,6 @@
  * SUCH DAMAGE.
  */
 
-#undef _FORTIFY_SOURCE
 #include <errno.h>
 #include <malloc.h>
 #include <string.h>
diff --git a/libc/bionic/poll.cpp b/libc/bionic/poll.cpp
index eded56a..dbc9584 100644
--- a/libc/bionic/poll.cpp
+++ b/libc/bionic/poll.cpp
@@ -26,7 +26,6 @@
  * SUCH DAMAGE.
  */
 
-#undef _FORTIFY_SOURCE
 #include <errno.h>
 #include <sys/poll.h>
 #include <sys/select.h>
diff --git a/libc/bionic/readlink.cpp b/libc/bionic/readlink.cpp
index a53f933..3bb7bc1 100644
--- a/libc/bionic/readlink.cpp
+++ b/libc/bionic/readlink.cpp
@@ -26,8 +26,6 @@
  * SUCH DAMAGE.
  */
 
-#undef _FORTIFY_SOURCE
-
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
diff --git a/libc/bionic/recv.cpp b/libc/bionic/recv.cpp
index 061cd46..60f264d 100644
--- a/libc/bionic/recv.cpp
+++ b/libc/bionic/recv.cpp
@@ -26,7 +26,6 @@
  * SUCH DAMAGE.
  */
 
-#undef _FORTIFY_SOURCE
 #include <sys/socket.h>
 
 ssize_t recv(int socket, void *buf, size_t len, int flags) {
diff --git a/libc/bionic/strchr.cpp b/libc/bionic/strchr.cpp
index 5bd3f19..fd8a924 100644
--- a/libc/bionic/strchr.cpp
+++ b/libc/bionic/strchr.cpp
@@ -27,7 +27,6 @@
  * SUCH DAMAGE.
  */
 
-#undef _FORTIFY_SOURCE
 #include <string.h>
 
 char* strchr(const char* p, int ch) {
diff --git a/libc/bionic/strrchr.cpp b/libc/bionic/strrchr.cpp
index 3fdb47c..b6c40f4 100644
--- a/libc/bionic/strrchr.cpp
+++ b/libc/bionic/strrchr.cpp
@@ -27,7 +27,6 @@
  * SUCH DAMAGE.
  */
 
-#undef _FORTIFY_SOURCE
 #include <string.h>
 
 char* strrchr(const char* p, int ch) {