diff --git a/man5/utmp.5 b/man5/utmp.5
index f95ef0f9e..50efb4521 100644
--- a/man5/utmp.5
+++ b/man5/utmp.5
@@ -52,39 +52,53 @@ around; details depend on the version of libc):
 .nf
 .sp
 .ta 3i
-#define UT_UNKNOWN	0
-#define RUN_LVL		1
-#define BOOT_TIME	2
-#define NEW_TIME	3
-#define OLD_TIME	4
-#define INIT_PROCESS	5
-#define LOGIN_PROCESS	6
-#define USER_PROCESS	7
-#define DEAD_PROCESS	8
-#define ACCOUNTING	9
+#define UT_UNKNOWN      0
+#define RUN_LVL         1
+#define BOOT_TIME       2
+#define NEW_TIME        3
+#define OLD_TIME        4
+#define INIT_PROCESS    5
+#define LOGIN_PROCESS   6
+#define USER_PROCESS    7
+#define DEAD_PROCESS    8
+#define ACCOUNTING      9
 
-#define UT_LINESIZE	12
-#define UT_NAMESIZE	32
-#define UT_HOSTSIZE	256
+#define UT_LINESIZE     12
+#define UT_NAMESIZE     32
+#define UT_HOSTSIZE     256
 
 struct exit_status {
-  short int e_termination;	/* process termination status.  */
-  short int e_exit;	/* process exit status.  */
+  short int e_termination;    /* process termination status */
+  short int e_exit;           /* process exit status */
 };
 
 struct utmp {
-  short ut_type;	/* type of login */
-  pid_t ut_pid;	/* PID of login process */
-  char ut_line[UT_LINESIZE];	/* device name of tty \- "/dev/" */
-  char ut_id[4];	/* init id or abbrev. ttyname */
-  char ut_user[UT_NAMESIZE];	/* user name */
-  char ut_host[UT_HOSTSIZE];	/* hostname for remote login */
-  struct exit_status ut_exit;	/* The exit status of a process
-	   marked as DEAD_PROCESS. */
-  long ut_session;	/* session ID, used for windowing*/
-  struct timeval ut_tv;	/* time entry was made.  */
-  int32_t ut_addr_v6[4];	/* IP address of remote host.  */
-  char __unused[20];	/* Reserved for future use.  */
+  short ut_type;              /* type of login */
+  pid_t ut_pid;               /* PID of login process */
+  char ut_line[UT_LINESIZE];  /* device name of tty \- "/dev/" */
+  char ut_id[4];              /* init id or abbrev. ttyname */
+  char ut_user[UT_NAMESIZE];  /* user name */
+  char ut_host[UT_HOSTSIZE];  /* hostname for remote login */
+  struct exit_status ut_exit; /* The exit status of a process
+                                 marked as DEAD_PROCESS */
+  
+  /* The ut_session and ut_tv fields must be the same size when 
+     compiled 32- and 64-bit.  This allows data files and shared 
+     memory to be shared between 32- and 64-bit applications */
+#if __WORDSIZE == 64 && defined __WORDSIZE_COMPAT32
+   int32_t ut_session;        /* Session ID, used for windowing */
+   struct
+   {
+   int32_t tv_sec;            /* Seconds */
+   int32_t tv_usec;           /* Microseconds */
+   } ut_tv;                   /* Time entry was made */
+#else
+   long int ut_session;       /* Session ID, used for windowing */
+   struct timeval ut_tv;      /* Time entry was made */
+#endif
+
+  int32_t ut_addr_v6[4];     /* IP address of remote host */
+  char __unused[20];         /* Reserved for future use */
 };
 
 /* Backwards compatibility hacks.  */
@@ -176,6 +190,33 @@ and some versions of
 .BR getty (1).
 Neither of these programs creates the file, so if it is
 removed, record-keeping is turned off.
+.PP
+Note that on \fBbiarch\fP platforms, i.e. systems which can run both
+32-bit and 64-bit applications (x86-64, ppc64, s390x, etc.),
+\fIut_tv\fP is the same size in 32-bit mode as in 64-bit mode.
+The same goes for \fIut_session\fP and \fIut_time\fP if they are present.
+This allows data files and shared memory to be shared between
+32-bit and 64-bit applications. 
+.\" FIXEME -- maybe include the following (MTK, 15 Sep 2005)
+.\" The following example is the recommended
+.\" method for filling in the \fIut_tv\fP member:
+.\" .RS
+.\" .nf
+.\" .sp
+.\" .ta 3i
+.\" struct utmp ut;
+.\" ...
+.\" if (sizeof (ut.ut_tv) == sizeof (struct timeval))
+.\"   gettimeofday((struct timeval *) &ut.ut_tv, NULL);
+.\" else {
+.\"   struct timeval tv;
+.\"   gettimeofday(&tv, NULL);
+.\"   ut.ut_tv.tv_sec = tv.tv_sec;
+.\"   ut.ut_tv.tv_usec = tv.tv_usec;
+.\" }
+.\" .SP
+.\" .fi
+.\" .RE
 .SH FILES
 /var/run/utmp
 .br