Index: man.c
===================================================================
RCS file: /cvsroot/src/usr.bin/man/man.c,v
retrieving revision 1.66
diff -u -r1.66 man.c
--- man.c	2 May 2017 14:19:23 -0000	1.66
+++ man.c	11 Sep 2017 00:07:53 -0000
@@ -217,11 +217,14 @@
 		if (!isatty(STDOUT_FILENO)) {
 			m.cat = 1;
 		} else {
-			if ((m.pager = getenv("PAGER")) != NULL &&
-			    m.pager[0] != '\0')
-				m.pager = check_pager(m.pager);
-			else
+			m.pager = getenv("MANPAGER");
+			if (!m.pager || m.pager[0] == '\0')
+				m.pager = getenv("PAGER");
+			if (!m.pager || m.pager[0] == '\0')
 				m.pager = _PATH_PAGER;
+
+			m.pager = check_pager(m.pager);
+
 			m.pagerlen = strlen(m.pager);
 		}
 	}