diff --git a/usr.bin/w/pr_time.c b/usr.bin/w/pr_time.c
index 6faf6db10ecd..c48f6a7cf738 100644
--- a/usr.bin/w/pr_time.c
+++ b/usr.bin/w/pr_time.c
@@ -76,7 +76,8 @@ pr_attime(started, now)
 		(void)strcpy(fmt, __CONCAT("%l:%", "M%p"));
 	}
 
-	(void)strftime(buf, sizeof(buf), fmt, tp);
+	(void)strftime(buf, sizeof(buf) - 1, fmt, tp);
+	buf[sizeof(buf) - 1] = '\0';
 	(void)printf("%s", buf);
 }
 
diff --git a/usr.bin/w/w.c b/usr.bin/w/w.c
index c615430c04d6..f02799717b61 100644
--- a/usr.bin/w/w.c
+++ b/usr.bin/w/w.c
@@ -377,8 +377,9 @@ pr_header(nowp, nusers)
 	 * SCCS forces the string manipulation below, as it replaces
 	 * %, M, and % in a character string with the file name.
 	 */
-	(void)strftime(buf, sizeof(buf),
+	(void)strftime(buf, sizeof(buf) - 1,
 	    __CONCAT("%l:%","M%p"), localtime(nowp));
+	buf[sizeof(buf) - 1] = '\0';
 	(void)printf("%s ", buf);
 
 	/*