diff --git a/ChangeLog b/ChangeLog
index 5b0a0bd83c..0ec9284ce8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2017-03-17  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #21260]
+	* sysdeps/unix/sysv/linux/alpha/Makefile
+	[$(subdir) = conform] (conformtest-xfail-conds): New variable.
+
 	* conform/conformtest.pl ($cross): New variable.
 	(--cross): New command-line option.
 	(runtest): Skip test execution when cross-compiling.
diff --git a/conform/data/netdb.h-data b/conform/data/netdb.h-data
index 63a42ae179..7258a51ff7 100644
--- a/conform/data/netdb.h-data
+++ b/conform/data/netdb.h-data
@@ -15,7 +15,8 @@ type {struct netent}
 element {struct netent} {char*} n_name
 element {struct netent} {char**} n_aliases
 element {struct netent} int n_addrtype
-element {struct netent} uint32_t n_net
+// Bug 21260: n_net has wrong type.
+xfail[alpha-linux]-element {struct netent} uint32_t n_net
 
 type uint32_t
 
diff --git a/sysdeps/unix/sysv/linux/alpha/Makefile b/sysdeps/unix/sysv/linux/alpha/Makefile
index 4bbe9bf850..37bdd5a3d0 100644
--- a/sysdeps/unix/sysv/linux/alpha/Makefile
+++ b/sysdeps/unix/sysv/linux/alpha/Makefile
@@ -39,3 +39,8 @@ ifeq ($(subdir),nptl)
 libpthread-routines += sysdep sigprocmask rt_sigaction
 libpthread-shared-only-routines += sysdep sigprocmask rt_sigaction
 endif
+
+ifeq ($(subdir),conform)
+# For bug 21260.
+conformtest-xfail-conds += alpha-linux
+endif