--- a/sys/vm/vm_zone.c
+++ b/sys/vm/vm_zone.c
@@ -833,8 +833,8 @@
 		int n;
 
 		len = strlen(curzone->zname);
-		if (len >= (sizeof(tmpname) - 1))
-			len = (sizeof(tmpname) - 1);
+		if (len >= (sizeof(tmpname) - 2))
+			len = (sizeof(tmpname) - 2);
 		for(i = 0; i < sizeof(tmpname) - 1; i++)
 			tmpname[i] = ' ';
 		tmpname[i] = 0;