diff --git a/libc/Android.mk b/libc/Android.mk
index fc61c27..c7478c5 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -188,6 +188,7 @@
 
 # Fortify implementations of libc functions.
 libc_common_src_files += \
+    bionic/__FD_chk.cpp \
     bionic/__fgets_chk.cpp \
     bionic/__memcpy_chk.cpp \
     bionic/__memmove_chk.cpp \
diff --git a/libc/bionic/__FD_chk.cpp b/libc/bionic/__FD_chk.cpp
new file mode 100644
index 0000000..c4b55de
--- /dev/null
+++ b/libc/bionic/__FD_chk.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#undef _FORTIFY_SOURCE
+#include <sys/select.h>
+#include "libc_logging.h"
+
+extern "C" int __FD_ISSET_chk(int fd, fd_set* set) {
+  if (__predict_false(fd < 0)) {
+    __fortify_chk_fail("file descriptor is negative for FD_ISSET", 0);
+  }
+  if (__predict_false(fd >= FD_SETSIZE)) {
+    __fortify_chk_fail("file descriptor is too big for FD_ISSET", 0);
+  }
+  return FD_ISSET(fd, set);
+}
+
+extern "C" void __FD_CLR_chk(int fd, fd_set* set) {
+  if (__predict_false(fd < 0)) {
+    __fortify_chk_fail("file descriptor is negative for FD_CLR", 0);
+  }
+  if (__predict_false(fd >= FD_SETSIZE)) {
+    __fortify_chk_fail("file descriptor is too big for FD_CLR", 0);
+  }
+  FD_CLR(fd, set);
+}
+
+extern "C" void __FD_SET_chk(int fd, fd_set* set) {
+  if (__predict_false(fd < 0)) {
+    __fortify_chk_fail("file descriptor is negative for FD_SET", 0);
+  }
+  if (__predict_false(fd >= FD_SETSIZE)) {
+    __fortify_chk_fail("file descriptor is too big for FD_SET", 0);
+  }
+  FD_SET(fd, set);
+}
diff --git a/libc/include/sys/select.h b/libc/include/sys/select.h
index 8d77957..c8cd8e1 100644
--- a/libc/include/sys/select.h
+++ b/libc/include/sys/select.h
@@ -46,14 +46,23 @@
 #define __FDELT(fd) ((fd) / __NFDBITS)
 #define __FDMASK(fd) (1UL << ((fd) % __NFDBITS))
 #define __FDS_BITS(set) (((fd_set*)(set))->fds_bits)
-
 #define __FD_CLR(fd, set) (__FDS_BITS(set)[__FDELT(fd)] &= ~__FDMASK(fd))
 #define __FD_SET(fd, set) (__FDS_BITS(set)[__FDELT(fd)] |= __FDMASK(fd))
-
 #define __FD_ISSET(fd, set) ((__FDS_BITS(set)[__FDELT(fd)] & __FDMASK(fd)) != 0)
-
 #define __FD_ZERO(set) (__builtin_memset(set, 0, sizeof(*(fd_set*)(set))))
 
+#if defined(__BIONIC_FORTIFY)
+extern void __FD_CLR_chk(int, fd_set*);
+extern void __FD_SET_chk(int, fd_set*);
+extern int  __FD_ISSET_chk(int, fd_set*);
+#undef __FD_CLR
+#undef __FD_SET
+#undef __FD_ISSET
+#define __FD_CLR(fd, set) __FD_CLR_chk(fd, set)
+#define __FD_SET(fd, set) __FD_SET_chk(fd, set)
+#define __FD_ISSET(fd, set) __FD_ISSET_chk(fd, set)
+#endif /* defined(__BIONIC_FORTIFY) */
+
 extern int select(int, fd_set*, fd_set*, fd_set*, struct timeval*);
 extern int pselect(int n, fd_set* read_fds, fd_set* write_fds, fd_set* err_fds,
                    const struct timespec * timeout, const sigset_t* sigmask);