diff --git a/libc/bionic/__fgets_chk.cpp b/libc/bionic/__fgets_chk.cpp
index 61dad7077997c9e2b18be11190c62ebf5035b030..c09f6c53163faa6a070e135289da3f87ba478d87 100644
--- a/libc/bionic/__fgets_chk.cpp
+++ b/libc/bionic/__fgets_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include "private/libc_logging.h"
diff --git a/libc/bionic/__memmove_chk.cpp b/libc/bionic/__memmove_chk.cpp
index 26bd646cdaad863c548a104b1e4ad601221c5246..b88a94f76f1dc182f5248f64d988f54079c17edd 100644
--- a/libc/bionic/__memmove_chk.cpp
+++ b/libc/bionic/__memmove_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <string.h>
 #include <stdlib.h>
 #include "private/libc_logging.h"
diff --git a/libc/bionic/__memset_chk.cpp b/libc/bionic/__memset_chk.cpp
index 9a3be19ddf9c91efc8927990a3ba13d81f699625..5f20452f52d63ed4fc43cdc303318be8486efbb5 100644
--- a/libc/bionic/__memset_chk.cpp
+++ b/libc/bionic/__memset_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <string.h>
 #include <stdlib.h>
 #include "private/libc_logging.h"
diff --git a/libc/bionic/__strlcat_chk.cpp b/libc/bionic/__strlcat_chk.cpp
index f583154ae373f2450e4c1c0d6bf10bbf0d97eeac..2b7373b9dc4d16668af2bcee88c16032a0b1e334 100644
--- a/libc/bionic/__strlcat_chk.cpp
+++ b/libc/bionic/__strlcat_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <string.h>
 #include <stdlib.h>
 #include "private/libc_logging.h"
diff --git a/libc/bionic/__strlcpy_chk.cpp b/libc/bionic/__strlcpy_chk.cpp
index ebf1444b94111a763469397dea5f1822fb5311d0..6b2187932a80a91a25015bc3f4705c302f2dc846 100644
--- a/libc/bionic/__strlcpy_chk.cpp
+++ b/libc/bionic/__strlcpy_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <string.h>
 #include <stdlib.h>
 #include "private/libc_logging.h"
diff --git a/libc/bionic/__strncpy_chk.cpp b/libc/bionic/__strncpy_chk.cpp
index 76458aa74b28fc6aa8b9b1839d402d26b76e400a..9625929cd45cbcb801c1edca79e9d0e472f15331 100644
--- a/libc/bionic/__strncpy_chk.cpp
+++ b/libc/bionic/__strncpy_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <string.h>
 #include <stdlib.h>
 #include "private/libc_logging.h"
diff --git a/libc/bionic/__vsnprintf_chk.cpp b/libc/bionic/__vsnprintf_chk.cpp
index 8550224b391229c27630beea63dc5150480e0c77..8c0911162ed383cd5bc7ff949c5936262d5a1d1f 100644
--- a/libc/bionic/__vsnprintf_chk.cpp
+++ b/libc/bionic/__vsnprintf_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
diff --git a/libc/bionic/__vsprintf_chk.cpp b/libc/bionic/__vsprintf_chk.cpp
index bd2aeaba5301061cd1dc3abf8c6deaafcc92d2ad..5914026b05176c4cf67cd0793bee98841a34cd5d 100644
--- a/libc/bionic/__vsprintf_chk.cpp
+++ b/libc/bionic/__vsprintf_chk.cpp
@@ -26,6 +26,8 @@
  * SUCH DAMAGE.
  */
 
+#undef _FORTIFY_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>