diff --git a/man2/faccessat.2 b/man2/faccessat.2
index e29d61e13..4143224d3 100644
--- a/man2/faccessat.2
+++ b/man2/faccessat.2
@@ -30,7 +30,7 @@ directory file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
-.B #include <fcntl.h>
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <unistd.h>
 .sp
 .BI "int faccessat(int " dirfd ", const char *" pathname ", int " \
diff --git a/man2/fchmodat.2 b/man2/fchmodat.2
index 334e6dba5..50f7e308d 100644
--- a/man2/fchmodat.2
+++ b/man2/fchmodat.2
@@ -30,6 +30,7 @@ file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <sys/stat.h>
 .sp
 .BI "int fchmodat(int " dirfd ", const char *" pathname ", mode_t " \
diff --git a/man2/fchownat.2 b/man2/fchownat.2
index f655d11e9..5f6806340 100644
--- a/man2/fchownat.2
+++ b/man2/fchownat.2
@@ -30,6 +30,7 @@ file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <unistd.h>
 .sp
 .BI "int fchownat(int " dirfd ", const char *" pathname ,
diff --git a/man2/fstatat.2 b/man2/fstatat.2
index faa98286a..d9ae94167 100644
--- a/man2/fstatat.2
+++ b/man2/fstatat.2
@@ -29,6 +29,7 @@ fstatat \- get file status relative to a directory file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <sys/stat.h>
 .sp
 .BI "int fstatat(int " dirfd ", const char *" pathname ", struct stat *" \
diff --git a/man2/futimesat.2 b/man2/futimesat.2
index 9f0526ea4..d00da22cf 100644
--- a/man2/futimesat.2
+++ b/man2/futimesat.2
@@ -30,6 +30,7 @@ directory file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <fcntl.h>
 .sp
 .BI "int futimesat(int " dirfd ", const char *" pathname ,
diff --git a/man2/linkat.2 b/man2/linkat.2
index 17fa432e7..90521d060 100644
--- a/man2/linkat.2
+++ b/man2/linkat.2
@@ -29,6 +29,7 @@ linkat \- create a file link relative to directory file descriptors
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <unistd.h>
 .sp
 .BI "int linkat(int " olddirfd ", const char *" oldpath ,
diff --git a/man2/mkdirat.2 b/man2/mkdirat.2
index 7644ed782..8d48c7e13 100644
--- a/man2/mkdirat.2
+++ b/man2/mkdirat.2
@@ -25,6 +25,7 @@
 .\"
 .TH MKDIRAT 2 2006-04-06 "Linux" "Linux Programmer's Manual"
 .SH NAME
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 mkdirat \- create a directory relative to a directory file descriptor
 .SH SYNOPSIS
 .nf
diff --git a/man2/mknodat.2 b/man2/mknodat.2
index 60edd3c33..72dc03338 100644
--- a/man2/mknodat.2
+++ b/man2/mknodat.2
@@ -30,6 +30,7 @@ file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <sys/stat.h>
 .sp
 .BI "int mknodat(int " dirfd ", const char *" pathname ", mode_t " mode \
diff --git a/man2/readlinkat.2 b/man2/readlinkat.2
index 05e7887c4..15de5ff7b 100644
--- a/man2/readlinkat.2
+++ b/man2/readlinkat.2
@@ -30,6 +30,7 @@ a directory file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <unistd.h>
 .sp
 .BI "int readlinkat(int " dirfd ", const char *" pathname ,
diff --git a/man2/renameat.2 b/man2/renameat.2
index deaf90d5b..91aeb65a7 100644
--- a/man2/renameat.2
+++ b/man2/renameat.2
@@ -29,6 +29,7 @@ renameat \- rename a file relative to directory file descriptors
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <stdio.h>
 .sp
 .BI "int renameat(int " olddirfd ", const char *" oldpath ,
diff --git a/man2/symlinkat.2 b/man2/symlinkat.2
index 6257c92a6..05e27f41d 100644
--- a/man2/symlinkat.2
+++ b/man2/symlinkat.2
@@ -29,6 +29,7 @@ symlinkat \- create a symbolic link relative to a directory file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <stdio.h>
 .sp
 .BI "int symlinkat(const char *" oldpath ", int " newdirfd \
diff --git a/man3/mkfifoat.3 b/man3/mkfifoat.3
index 0f7841d80..6e70e967d 100644
--- a/man3/mkfifoat.3
+++ b/man3/mkfifoat.3
@@ -29,6 +29,7 @@ mkfifoat \- make a FIFO (named pipe) relative to a directory file descriptor
 .SH SYNOPSIS
 .nf
 .B #define _ATFILE_SOURCE
+.B #include <fcntl.h>           /* Definition of AT_* constants */
 .B #include <sys/stat.h>
 .sp
 .BI "int mkfifoat(int " dirfd ", const char *" pathname ", mode_t " mode );