diff -urp a/usr.bin/mandoc/chars.c b/usr.bin/mandoc/chars.c
--- a/usr.bin/mandoc/chars.c	Thu Feb 13 19:16:03 2020
+++ b/usr.bin/mandoc/chars.c	Mon Oct 19 13:02:28 2020
@@ -16,6 +16,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#include <sys/cdefs.h>
 #include <sys/types.h>
 
 #include <assert.h>
diff -urp a/usr.bin/mandoc/dba.c b/usr.bin/mandoc/dba.c
--- a/usr.bin/mandoc/dba.c	Thu Feb  9 21:26:17 2017
+++ b/usr.bin/mandoc/dba.c	Mon Oct 19 13:02:28 2020
@@ -17,6 +17,7 @@
  * Allocation-based version of the mandoc database, for read-write access.
  * The interface is defined in "dba.h".
  */
+#include <sys/cdefs.h>
 #include <sys/types.h>
 #include <endian.h>
 #include <errno.h>
diff -urp a/usr.bin/mandoc/dbm.c b/usr.bin/mandoc/dbm.c
--- a/usr.bin/mandoc/dbm.c	Tue Jul  2 01:43:03 2019
+++ b/usr.bin/mandoc/dbm.c	Mon Oct 19 13:02:28 2020
@@ -31,6 +31,10 @@
 #include "dbm_map.h"
 #include "dbm.h"
 
+#ifndef EFTYPE
+#define EFTYPE 79
+#endif
+
 struct macro {
 	int32_t	value;
 	int32_t	pages;
diff -urp a/usr.bin/mandoc/dbm_map.c b/usr.bin/mandoc/dbm_map.c
--- a/usr.bin/mandoc/dbm_map.c	Thu Feb  9 21:26:17 2017
+++ b/usr.bin/mandoc/dbm_map.c	Mon Oct 19 13:02:28 2020
@@ -36,6 +36,10 @@
 #include "dbm_map.h"
 #include "dbm.h"
 
+#ifndef EFTYPE
+#define EFTYPE 79
+#endif
+
 static struct stat	 st;
 static char		*dbm_base;
 static int		 ifd;
diff -urp a/usr.bin/mandoc/html.c b/usr.bin/mandoc/html.c
--- a/usr.bin/mandoc/html.c	Mon Apr 20 15:59:24 2020
+++ b/usr.bin/mandoc/html.c	Mon Oct 19 13:02:28 2020
@@ -18,6 +18,7 @@
  * Common functions for mandoc(1) HTML formatters.
  * For use by individual formatters and by the main program.
  */
+#include <sys/cdefs.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 
diff -urp a/usr.bin/mandoc/main.c b/usr.bin/mandoc/main.c
--- a/usr.bin/mandoc/main.c	Tue Jul 21 18:08:48 2020
+++ b/usr.bin/mandoc/main.c	Mon Oct 19 13:28:19 2020
@@ -411,8 +411,10 @@ main(int argc, char *argv[])
 		}
 		if (search.arch == NULL)
 			search.arch = getenv("MACHINE");
+#ifdef MACHINE
 		if (search.arch == NULL)
 			search.arch = MACHINE;
+#endif
 		if (outmode == OUTMODE_ONE)
 			search.firstmatch = 1;
 	}
@@ -1199,7 +1201,9 @@ spawn_pager(struct outstate *outst, char *tag_target)
 	char		*argv[MAX_PAGER_ARGS];
 	const char	*pager;
 	char		*cp;
+#ifdef HAVE_LESS_T
 	size_t		 cmdlen;
+#endif
 	int		 argc, use_ofn;
 	pid_t		 pager_pid;
 
@@ -1234,6 +1238,7 @@ spawn_pager(struct outstate *outst, char *tag_target)
 	/* For more(1) and less(1), use the tag file. */
 
 	use_ofn = 1;
+#ifdef HAVE_LESS_T
 	if (*outst->tag_files->tfn != '\0' &&
 	    (cmdlen = strlen(argv[0])) >= 4) {
 		cp = argv[0] + cmdlen - 4;
@@ -1247,6 +1252,7 @@ spawn_pager(struct outstate *outst, char *tag_target)
 			}
 		}
 	}
+#endif
 	if (use_ofn) {
 		if (outst->outtype == OUTT_HTML && tag_target != NULL)
 			mandoc_asprintf(&argv[argc], "file://%s#%s",
diff -urp a/usr.bin/mandoc/mandoc_ohash.c b/usr.bin/mandoc/mandoc_ohash.c
--- a/usr.bin/mandoc/mandoc_ohash.c	Mon Oct 19 21:58:20 2015
+++ b/usr.bin/mandoc/mandoc_ohash.c	Mon Oct 19 13:02:28 2020
@@ -14,6 +14,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#include <sys/cdefs.h>
 #include <sys/types.h>
 #include <stddef.h>
 #include <stdint.h>
diff -urp a/usr.bin/mandoc/mandoc_xr.c b/usr.bin/mandoc/mandoc_xr.c
--- a/usr.bin/mandoc/mandoc_xr.c	Mon Jul  3 00:17:12 2017
+++ b/usr.bin/mandoc/mandoc_xr.c	Mon Oct 19 13:02:28 2020
@@ -14,6 +14,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#include <sys/cdefs.h>
 #include <sys/types.h>
 
 #include <assert.h>
diff -urp a/usr.bin/mandoc/mansearch.c b/usr.bin/mandoc/mansearch.c
--- a/usr.bin/mandoc/mansearch.c	Tue Jul  2 01:43:03 2019
+++ b/usr.bin/mandoc/mansearch.c	Mon Oct 19 13:02:28 2020
@@ -16,6 +16,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#include <sys/cdefs.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 
diff -urp a/usr.bin/mandoc/roff.c b/usr.bin/mandoc/roff.c
--- a/usr.bin/mandoc/roff.c	Thu Aug 27 15:58:00 2020
+++ b/usr.bin/mandoc/roff.c	Mon Oct 19 13:02:28 2020
@@ -17,6 +17,7 @@
  *
  * Implementation of the roff(7) parser for mandoc(1).
  */
+#include <sys/cdefs.h>
 #include <sys/types.h>
 
 #include <assert.h>
diff -urp a/usr.bin/mandoc/tag.c b/usr.bin/mandoc/tag.c
--- a/usr.bin/mandoc/tag.c	Sun Apr 19 19:26:11 2020
+++ b/usr.bin/mandoc/tag.c	Mon Oct 19 13:02:28 2020
@@ -17,6 +17,7 @@
  * Functions to tag syntax tree nodes.
  * For internal use by mandoc(1) validation modules only.
  */
+#include <sys/cdefs.h>
 #include <sys/types.h>
 
 #include <assert.h>