diff --git a/scripts/glibcextract.py b/scripts/glibcextract.py
index ecc4d5b6cc..06f712ad11 100644
--- a/scripts/glibcextract.py
+++ b/scripts/glibcextract.py
@@ -136,12 +136,19 @@ def compute_macro_consts(source_text, cc, macro_re, exclude_re=None):
     return compute_c_consts(sym_data, cc)
 
 
-def compare_macro_consts(source_1, source_2, cc, macro_re, exclude_re=None):
+def compare_macro_consts(source_1, source_2, cc, macro_re, exclude_re=None,
+                         allow_extra_1=False, allow_extra_2=False):
     """Compare the values of macros defined by two different sources.
 
     The sources would typically be includes of a glibc header and a
-    kernel header.  Return 1 if there were any differences, 0 if the
-    macro values were the same.
+    kernel header.  If allow_extra_1, the first source may define
+    extra macros (typically if the kernel headers are older than the
+    version glibc has taken definitions from); if allow_extra_2, the
+    second source may define extra macros (typically if the kernel
+    headers are newer than the version glibc has taken definitions
+    from).  Return 1 if there were any differences other than those
+    allowed, 0 if the macro values were the same apart from any
+    allowed differences.
 
     """
     macros_1 = compute_macro_consts(source_1, cc, macro_re, exclude_re)
@@ -150,13 +157,19 @@ def compare_macro_consts(source_1, source_2, cc, macro_re, exclude_re=None):
         return 0
     print('First source:\n%s\n' % source_1)
     print('Second source:\n%s\n' % source_2)
+    ret = 0
     for name, value in sorted(macros_1.items()):
         if name not in macros_2:
             print('Only in first source: %s' % name)
+            if not allow_extra_1:
+                ret = 1
         elif macros_1[name] != macros_2[name]:
             print('Different values for %s: %s != %s'
                   % (name, macros_1[name], macros_2[name]))
+            ret = 1
     for name in sorted(macros_2.keys()):
         if name not in macros_1:
             print('Only in second source: %s' % name)
-    return 1
+            if not allow_extra_2:
+                ret = 1
+    return ret
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index da44c274c6..0acdc7e41d 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -100,6 +100,15 @@ $(objpfx)tst-sysconf-iov_max: $(objpfx)tst-sysconf-iov_max-uapi.o
 
 $(objpfx)tst-pkey: $(shared-thread-library)
 
+tests-special += $(objpfx)tst-mman-consts.out
+$(objpfx)tst-mman-consts.out: ../sysdeps/unix/sysv/linux/tst-mman-consts.py
+	PYTHONPATH=../scripts \
+	$(PYTHON) ../sysdeps/unix/sysv/linux/tst-mman-consts.py \
+		   --cc="$(CC) $(patsubst -DMODULE_NAME=%, \
+					  -DMODULE_NAME=testsuite, \
+					  $(CPPFLAGS))" \
+	< /dev/null > $@ 2>&1; $(evaluate-test)
+
 endif # $(subdir) == misc
 
 ifeq ($(subdir),time)
diff --git a/sysdeps/unix/sysv/linux/tst-mman-consts.py b/sysdeps/unix/sysv/linux/tst-mman-consts.py
new file mode 100644
index 0000000000..1a613beec0
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-mman-consts.py
@@ -0,0 +1,65 @@
+#!/usr/bin/python3
+# Test that glibc's sys/mman.h constants match the kernel's.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import argparse
+import sys
+
+import glibcextract
+
+
+def linux_kernel_version(cc):
+    """Return the (major, minor) version of the Linux kernel headers."""
+    sym_data = ['#include <linux/version.h>', 'START',
+                ('LINUX_VERSION_CODE', 'LINUX_VERSION_CODE')]
+    val = glibcextract.compute_c_consts(sym_data, cc)['LINUX_VERSION_CODE']
+    val = int(val)
+    return ((val & 0xff0000) >> 16, (val & 0xff00) >> 8)
+
+
+def main():
+    """The main entry point."""
+    parser = argparse.ArgumentParser(
+        description="Test that glibc's sys/mman.h constants "
+        "match the kernel's.")
+    parser.add_argument('--cc', metavar='CC',
+                        help='C compiler (including options) to use')
+    args = parser.parse_args()
+    linux_version_headers = linux_kernel_version(args.cc)
+    linux_version_glibc = (4, 19)
+    sys.exit(glibcextract.compare_macro_consts(
+        '#define _GNU_SOURCE 1\n'
+        '#include <sys/mman.h>\n',
+        '#define _GNU_SOURCE 1\n'
+        '#include <linux/mman.h>\n',
+        args.cc,
+        'MAP_.*',
+        # A series of MAP_HUGE_<size> macros are defined by the kernel
+        # but not by glibc.  MAP_UNINITIALIZED is kernel-only.
+        # MAP_FAILED is not a MAP_* flag and is glibc-only, as is the
+        # MAP_ANON alias for MAP_ANONYMOUS.  MAP_RENAME, MAP_AUTOGROW,
+        # MAP_LOCAL and MAP_AUTORSRV are in the kernel header for
+        # MIPS, marked as "not used by linux"; SPARC has MAP_INHERIT
+        # in the kernel header, but does not use it.
+        'MAP_HUGE_[0-9].*|MAP_UNINITIALIZED|MAP_FAILED|MAP_ANON'
+        '|MAP_RENAME|MAP_AUTOGROW|MAP_LOCAL|MAP_AUTORSRV|MAP_INHERIT',
+        linux_version_glibc > linux_version_headers,
+        linux_version_headers > linux_version_glibc))
+
+if __name__ == '__main__':
+    main()
