diff --git a/bin/ps/keyword.c b/bin/ps/keyword.c
--- a/bin/ps/keyword.c
+++ b/bin/ps/keyword.c
@@ -36,7 +36,6 @@
 #include <sys/sysctl.h>
 #include <sys/user.h>
 
-#include <err.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -250,7 +249,8 @@
 	}
 	xo_emit("\n");
 	xo_close_list("key");
-	xo_finish();
+	if (xo_finish() < 0)
+		xo_err(1, "stdout");
 }
 
 void
@@ -291,7 +291,7 @@
 				continue;
 		}
 		if ((vent = malloc(sizeof(struct varent))) == NULL)
-			errx(1, "malloc failed");
+			xo_errx(1, "malloc failed");
 		vent->header = v->header;
 		if (hp) {
 			hp = strdup(hp);
@@ -300,13 +300,13 @@
 		}
 		vent->var = malloc(sizeof(*vent->var));
 		if (vent->var == NULL)
-			errx(1, "malloc failed");
+			xo_errx(1, "malloc failed");
 		memcpy(vent->var, v, sizeof(*vent->var));
 		STAILQ_INSERT_TAIL(&varlist, vent, next_ve);
 	}
 	free(tempstr1);
 	if (STAILQ_EMPTY(&varlist)) {
-		warnx("no valid keywords; valid keywords:");
+		xo_warnx("no valid keywords; valid keywords:");
 		showkey();
 		exit(1);
 	}
@@ -345,7 +345,7 @@
 			rflen = strlen(v->alias) + strlen(hp) + 2;
 			realfmt = malloc(rflen);
 			if (realfmt == NULL)
-				errx(1, "malloc failed");
+				xo_errx(1, "malloc failed");
 			snprintf(realfmt, rflen, "%s=%s", v->alias, hp);
 			parsefmt(realfmt, user);
 			free(realfmt);
@@ -353,7 +353,7 @@
 		return ((VAR *)NULL);
 	}
 	if (!v) {
-		warnx("%s: keyword not found", p);
+		xo_warnx("%s: keyword not found", p);
 		eval = 1;
 	}
 	if (header)
diff --git a/bin/ps/print.c b/bin/ps/print.c
--- a/bin/ps/print.c
+++ b/bin/ps/print.c
@@ -40,7 +40,6 @@
 #include <sys/sysctl.h>
 #include <sys/vmmeter.h>
 
-#include <err.h>
 #include <grp.h>
 #include <jail.h>
 #include <langinfo.h>
diff --git a/bin/ps/ps.c b/bin/ps/ps.c
--- a/bin/ps/ps.c
+++ b/bin/ps/ps.c
@@ -46,7 +46,6 @@
 #include <sys/mount.h>
 
 #include <ctype.h>
-#include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <grp.h>
@@ -657,7 +656,8 @@
 
 	if (nkept == 0) {
 		printheader();
-		xo_finish();
+		if (xo_finish() < 0)
+			xo_err(1, "stdout");
 		exit(1);
 	}
 
@@ -742,7 +742,8 @@
 	}
 	xo_close_list("process");
 	xo_close_container("process-information");
-	xo_finish();
+	if (xo_finish() < 0)
+		xo_err(1, "stdout");
 
 	free_list(&gidlist);
 	free_list(&jidlist);
@@ -812,14 +813,14 @@
 	int tempid;
 
 	if (*elem == '\0') {
-		warnx("Invalid (zero-length) jail id");
+		xo_warnx("Invalid (zero-length) jail id");
 		optfatal = 1;
 		return (0);		/* Do not add this value. */
 	}
 
 	tempid = jail_getid(elem);
 	if (tempid < 0) {
-		warnx("Invalid %s: %s", inf->lname, elem);
+		xo_warnx("Invalid %s: %s", inf->lname, elem);
 		optfatal = 1;
 		return (0);
 	}
@@ -1480,7 +1481,7 @@
 {
 #define	SINGLE_OPTS	"[-aCcde" OPT_LAZY_f "HhjlmrSTuvwXxZ]"
 
-	(void)xo_error("%s\n%s\n%s\n%s\n%s\n",
+	xo_error("%s\n%s\n%s\n%s\n%s\n",
 	    "usage: ps [--libxo] " SINGLE_OPTS " [-O fmt | -o fmt]",
 	    "          [-G gid[,gid...]] [-J jid[,jid...]] [-M core] [-N system]",
 	    "          [-p pid[,pid...]] [-t tty[,tty...]] [-U user[,user...]]",